diff --git a/action.h b/action.h
index 104ef9e..45c6430 100644
--- a/action.h
+++ b/action.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_H_
 
 #include <stdio.h>
 #include <tr1/memory>
@@ -200,4 +200,4 @@
 
 };  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_H_
diff --git a/action_mock.h b/action_mock.h
index 4ebafba..07f435e 100644
--- a/action_mock.h
+++ b/action_mock.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_MOCK_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_MOCK_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_MOCK_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_MOCK_H_
 
 #include <gmock/gmock.h>
 
@@ -28,4 +28,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_MOCK_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_MOCK_H_
diff --git a/action_pipe.h b/action_pipe.h
index a59c210..8e4f761 100644
--- a/action_pipe.h
+++ b/action_pipe.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PIPE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PIPE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PIPE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PIPE_H_
 
 #include <stdio.h>
 #include <iostream>
@@ -86,4 +86,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PIPE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PIPE_H_
diff --git a/action_processor.h b/action_processor.h
index 696afd4..32457a8 100644
--- a/action_processor.h
+++ b/action_processor.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_H_
 
 #include <deque>
 
@@ -99,4 +99,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_H_
diff --git a/action_processor_mock.h b/action_processor_mock.h
index f4f1103..696a0b6 100644
--- a/action_processor_mock.h
+++ b/action_processor_mock.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_MOCK_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_MOCK_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_MOCK_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_MOCK_H_
 
 #include <gmock/gmock.h>
 
@@ -19,4 +19,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_MOCK_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_MOCK_H_
diff --git a/bzip.h b/bzip.h
index ca6e881..4f70d74 100644
--- a/bzip.h
+++ b/bzip.h
@@ -1,7 +1,10 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_BZIP_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_BZIP_H_
+
 #include <string>
 #include <vector>
 
@@ -14,3 +17,5 @@
 bool BzipDecompressString(const std::string& str, std::vector<char>* out);
 
 }  // namespace chromeos_update_engine
+
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_BZIP_H_
diff --git a/bzip_extent_writer.h b/bzip_extent_writer.h
index acffbac..cf9f2cb 100644
--- a/bzip_extent_writer.h
+++ b/bzip_extent_writer.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_BZIP_EXTENT_WRITER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_BZIP_EXTENT_WRITER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_BZIP_EXTENT_WRITER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_BZIP_EXTENT_WRITER_H_
 
 #include <vector>
 #include <bzlib.h>
@@ -35,4 +35,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_BZIP_EXTENT_WRITER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_BZIP_EXTENT_WRITER_H_
diff --git a/certificate_checker_mock.h b/certificate_checker_mock.h
index 55668a1..78c44b7 100644
--- a/certificate_checker_mock.h
+++ b/certificate_checker_mock.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_UPDATE_ENGINE_CERTIFICATE_CHECKER_MOCK_H_
-#define CHROMEOS_UPDATE_ENGINE_CERTIFICATE_CHECKER_MOCK_H_
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CERTIFICATE_CHECKER_MOCK_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CERTIFICATE_CHECKER_MOCK_H_
 
 #include <gmock/gmock.h>
 #include <openssl/ssl.h>
@@ -23,4 +23,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_UPDATE_ENGINE_CERTIFICATE_CHECKER_MOCK_H_
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CERTIFICATE_CHECKER_MOCK_H_
diff --git a/chrome_browser_proxy_resolver.h b/chrome_browser_proxy_resolver.h
index 1783aef..6ec88a2 100644
--- a/chrome_browser_proxy_resolver.h
+++ b/chrome_browser_proxy_resolver.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CHROME_BROWSER_PROXY_RESOLVER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CHROME_BROWSER_PROXY_RESOLVER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CHROME_BROWSER_PROXY_RESOLVER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CHROME_BROWSER_PROXY_RESOLVER_H_
 
 #include <map>
 #include <string>
@@ -86,4 +86,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CHROME_BROWSER_PROXY_RESOLVER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CHROME_BROWSER_PROXY_RESOLVER_H_
diff --git a/clock.h b/clock.h
index 8cfe366..7d989d0 100644
--- a/clock.h
+++ b/clock.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_H_
 
 #include "update_engine/clock_interface.h"
 
@@ -27,4 +27,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_H_
diff --git a/clock_interface.h b/clock_interface.h
index d9e6124..cd714b1 100644
--- a/clock_interface.h
+++ b/clock_interface.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_INTERFACE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_INTERFACE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_INTERFACE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_INTERFACE_H_
 
 #include <string>
 
@@ -39,4 +39,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_INTERFACE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CLOCK_INTERFACE_H_
diff --git a/constants.h b/constants.h
index ae9bde8..cb63d1a 100644
--- a/constants.h
+++ b/constants.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CONSTANTS_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CONSTANTS_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CONSTANTS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CONSTANTS_H_
 
 namespace chromeos_update_engine {
 
@@ -157,4 +157,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CONSTANTS_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CONSTANTS_H_
diff --git a/cycle_breaker.h b/cycle_breaker.h
index f1fa677..8bf2a3e 100644
--- a/cycle_breaker.h
+++ b/cycle_breaker.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CYCLE_BREAKER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CYCLE_BREAKER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_CYCLE_BREAKER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_CYCLE_BREAKER_H_
 
 // This is a modified implementation of Donald B. Johnson's algorithm for
 // finding all elementary cycles (a.k.a. circuits) in a directed graph.
@@ -55,4 +55,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CYCLE_BREAKER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CYCLE_BREAKER_H_
diff --git a/dbus_constants.h b/dbus_constants.h
index 625ac8d..849ba0b 100644
--- a/dbus_constants.h
+++ b/dbus_constants.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_CONSTANTS_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_CONSTANTS_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_CONSTANTS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_CONSTANTS_H_
 
 namespace chromeos_update_engine {
 
@@ -20,4 +20,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_CONSTANTS_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_CONSTANTS_H_
diff --git a/dbus_service.h b/dbus_service.h
index 32bb599..cb8c0e2 100644
--- a/dbus_service.h
+++ b/dbus_service.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_SERVICE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_SERVICE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_SERVICE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_SERVICE_H_
 
 #include <inttypes.h>
 #include <dbus/dbus-glib.h>
@@ -153,4 +153,4 @@
 
 G_END_DECLS
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_SERVICE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_SERVICE_H_
diff --git a/dbus_wrapper_interface.h b/dbus_wrapper_interface.h
index 9341174..51a268b 100644
--- a/dbus_wrapper_interface.h
+++ b/dbus_wrapper_interface.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_WRAPPER_H_
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_WRAPPER_H_
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_WRAPPER_INTERFACE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_WRAPPER_INTERFACE_H_
 
 // A mockable interface for DBus.
 
@@ -106,4 +106,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_WRAPPER_H_
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DBUS_WRAPPER_INTERFACE_H_
diff --git a/delta_diff_generator.h b/delta_diff_generator.h
index aec403a..2b620f0 100644
--- a/delta_diff_generator.h
+++ b/delta_diff_generator.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_DIFF_GENERATOR_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_DIFF_GENERATOR_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_DIFF_GENERATOR_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_DIFF_GENERATOR_H_
 
 #include <string>
 #include <vector>
@@ -273,4 +273,4 @@
 
 };  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_DIFF_GENERATOR_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_DIFF_GENERATOR_H_
diff --git a/delta_performer.h b/delta_performer.h
index 403ab8f..a95e4e1 100644
--- a/delta_performer.h
+++ b/delta_performer.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_PERFORMER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_PERFORMER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_PERFORMER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_PERFORMER_H_
 
 #include <inttypes.h>
 
@@ -361,4 +361,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_PERFORMER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DELTA_PERFORMER_H_
diff --git a/download_action.h b/download_action.h
index e6099f9..f77f6bc 100644
--- a/download_action.h
+++ b/download_action.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DOWNLOAD_ACTION_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DOWNLOAD_ACTION_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DOWNLOAD_ACTION_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_DOWNLOAD_ACTION_H_
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -150,4 +150,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DOWNLOAD_ACTION_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DOWNLOAD_ACTION_H_
diff --git a/error_code.h b/error_code.h
index 5853c1b..fc66ac9 100644
--- a/error_code.h
+++ b/error_code.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ERROR_CODE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ERROR_CODE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_ERROR_CODE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_ERROR_CODE_H_
 
 namespace chromeos_update_engine {
 
@@ -109,4 +109,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ACTION_PROCESSOR_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_ERROR_CODE_H_
diff --git a/extent_mapper.h b/extent_mapper.h
index e03ef21..821fb3e 100644
--- a/extent_mapper.h
+++ b/extent_mapper.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_MAPPER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_MAPPER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_MAPPER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_MAPPER_H_
 
 #include <string>
 #include <vector>
@@ -41,4 +41,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_MAPPER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_MAPPER_H_
diff --git a/extent_ranges.h b/extent_ranges.h
index 2ab347a..c559849 100644
--- a/extent_ranges.h
+++ b/extent_ranges.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_RANGES_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_RANGES_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_RANGES_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_RANGES_H_
 
 #include <map>
 #include <set>
@@ -72,4 +72,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_RANGES_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_RANGES_H_
diff --git a/extent_writer.h b/extent_writer.h
index 1bb6f4a..1b38ae6 100644
--- a/extent_writer.h
+++ b/extent_writer.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_WRITER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_WRITER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_WRITER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_WRITER_H_
 
 #include <vector>
 #include "base/logging.h"
@@ -118,4 +118,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_WRITER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_EXTENT_WRITER_H_
diff --git a/fake_clock.h b/fake_clock.h
index d920aaf..567e265 100644
--- a/fake_clock.h
+++ b/fake_clock.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_CLOCK_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_CLOCK_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_CLOCK_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_CLOCK_H_
 
 #include "update_engine/clock_interface.h"
 
@@ -48,4 +48,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_CLOCK_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_CLOCK_H_
diff --git a/fake_hardware.h b/fake_hardware.h
index ff572f9..161f51a 100644
--- a/fake_hardware.h
+++ b/fake_hardware.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_HARDWARE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_HARDWARE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_HARDWARE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_HARDWARE_H_
 
 #include <map>
 
@@ -104,4 +104,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_HARDWARE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_HARDWARE_H_
diff --git a/fake_p2p_manager.h b/fake_p2p_manager.h
index aebc238..1934e5a 100644
--- a/fake_p2p_manager.h
+++ b/fake_p2p_manager.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_H_
 
 #include "p2p_manager.h"
 
@@ -115,4 +115,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_H_
diff --git a/fake_p2p_manager_configuration.h b/fake_p2p_manager_configuration.h
index 9cc6481..79b6302 100644
--- a/fake_p2p_manager_configuration.h
+++ b/fake_p2p_manager_configuration.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_CONFIGURATION_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_CONFIGURATION_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_CONFIGURATION_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_CONFIGURATION_H_
 
 #include "update_engine/p2p_manager.h"
 #include "update_engine/utils.h"
@@ -117,4 +117,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_CONFIGURATION_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FAKE_P2P_MANAGER_CONFIGURATION_H_
diff --git a/file_descriptor.h b/file_descriptor.h
index 67d7b14..8a31180 100644
--- a/file_descriptor.h
+++ b/file_descriptor.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_DESCRIPTOR_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_DESCRIPTOR_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_DESCRIPTOR_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_DESCRIPTOR_H_
 
 #include <errno.h>
 #include <sys/types.h>
@@ -119,4 +119,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_DESCRIPTOR_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_DESCRIPTOR_H_
diff --git a/file_writer.h b/file_writer.h
index 57d0498..69d6ff9 100644
--- a/file_writer.h
+++ b/file_writer.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_H_
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -87,4 +87,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_H_
diff --git a/file_writer_mock.h b/file_writer_mock.h
index 004c3b1..02c8d97 100644
--- a/file_writer_mock.h
+++ b/file_writer_mock.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_MOCK_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_MOCK_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_MOCK_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_MOCK_H_
 
 #include "gmock/gmock.h"
 #include "update_engine/file_writer.h"
@@ -19,4 +19,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_MOCK_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILE_WRITER_MOCK_H_
diff --git a/filesystem_copier_action.h b/filesystem_copier_action.h
index c01fdeb..fce8e09 100644
--- a/filesystem_copier_action.h
+++ b/filesystem_copier_action.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_COPIER_ACTION_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_COPIER_ACTION_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_COPIER_ACTION_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_COPIER_ACTION_H_
 
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -141,4 +141,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_COPIER_ACTION_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_COPIER_ACTION_H_
diff --git a/filesystem_iterator.h b/filesystem_iterator.h
index a1ba8af..67908ab 100644
--- a/filesystem_iterator.h
+++ b/filesystem_iterator.h
@@ -1,9 +1,9 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_ITERATOR_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_ITERATOR_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_ITERATOR_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_ITERATOR_H_
 
 // This class is used to walk a filesystem. It will iterate over every file
 // on the same device as the file passed in the ctor. Directories will be
@@ -123,4 +123,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_ITERATOR_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FILESYSTEM_ITERATOR_H_
diff --git a/full_update_generator.h b/full_update_generator.h
index 4b9211c..29e3919 100644
--- a/full_update_generator.h
+++ b/full_update_generator.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FULL_UPDATE_GENERATOR_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FULL_UPDATE_GENERATOR_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_FULL_UPDATE_GENERATOR_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_FULL_UPDATE_GENERATOR_H_
 
 #include <glib.h>
 
@@ -38,4 +38,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FULL_UPDATE_GENERATOR_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_FULL_UPDATE_GENERATOR_H_
diff --git a/gpio_handler.h b/gpio_handler.h
index d1db7c2..580beb1 100644
--- a/gpio_handler.h
+++ b/gpio_handler.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_H_
 
 #include <libudev.h>
 
@@ -325,4 +325,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_H_
diff --git a/gpio_handler_unittest.h b/gpio_handler_unittest.h
index c98e248..484d1b8 100644
--- a/gpio_handler_unittest.h
+++ b/gpio_handler_unittest.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_UNITTEST_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_UNITTEST_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_UNITTEST_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_UNITTEST_H_
 
 // This file contains various definitions that are shared by different mock
 // implementations that emulate GPIO behavior in the system.
@@ -42,4 +42,4 @@
 
 }  // chromeos_update_engine
 
-#endif /* CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_UNITTEST_H__ */
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_HANDLER_UNITTEST_H_
diff --git a/gpio_mock_file_descriptor.h b/gpio_mock_file_descriptor.h
index c616b41..8c317ba 100644
--- a/gpio_mock_file_descriptor.h
+++ b/gpio_mock_file_descriptor.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_FILE_DESCRIPTOR_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_FILE_DESCRIPTOR_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_FILE_DESCRIPTOR_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_FILE_DESCRIPTOR_H_
 
 #include <base/rand_util.h>
 #include <base/time.h>
@@ -259,4 +259,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_FILE_DESCRIPTOR_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_FILE_DESCRIPTOR_H_
diff --git a/gpio_mock_udev_interface.h b/gpio_mock_udev_interface.h
index 04c29e0..759fa78 100644
--- a/gpio_mock_udev_interface.h
+++ b/gpio_mock_udev_interface.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_UDEV_INTERFACE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_UDEV_INTERFACE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_UDEV_INTERFACE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_UDEV_INTERFACE_H_
 
 #include "update_engine/gpio_handler.h"
 #include "update_engine/udev_interface.h"
@@ -146,4 +146,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_UDEV_INTERFACE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GPIO_MOCK_UDEV_INTERFACE_H_
diff --git a/graph_types.h b/graph_types.h
index f8d5afa..e460b1a 100644
--- a/graph_types.h
+++ b/graph_types.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_TYPES_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_TYPES_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_TYPES_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_TYPES_H_
 
 #include <map>
 #include <set>
@@ -79,4 +79,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_TYPES_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_TYPES_H_
diff --git a/graph_utils.h b/graph_utils.h
index 6f7b9a2..30b9c0b 100644
--- a/graph_utils.h
+++ b/graph_utils.h
@@ -1,9 +1,9 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_UTILS_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_UTILS_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_UTILS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_UTILS_H_
 
 #include <vector>
 #include "base/basictypes.h"
@@ -60,4 +60,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_UTILS_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_GRAPH_UTILS_H_
diff --git a/hardware.h b/hardware.h
index 02ed1ea..cad5699 100644
--- a/hardware.h
+++ b/hardware.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_H_
 
 #include "update_engine/hardware_interface.h"
 
@@ -36,4 +36,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_H_
diff --git a/hardware_interface.h b/hardware_interface.h
index f55d700..c22aef5 100644
--- a/hardware_interface.h
+++ b/hardware_interface.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_INTERFACE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_INTERFACE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_INTERFACE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_INTERFACE_H_
 
 #include <string>
 #include <vector>
@@ -61,4 +61,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_INTERFACE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HARDWARE_INTERFACE_H_
diff --git a/http_common.h b/http_common.h
index b2ffbc7..2c52445 100644
--- a/http_common.h
+++ b/http_common.h
@@ -5,8 +5,8 @@
 // This file contains general definitions used in implementing, testing and
 // emulating communication over HTTP.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_COMMON_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_COMMON_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_COMMON_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_COMMON_H_
 
 #include <stdlib.h>
 
@@ -55,4 +55,4 @@
 // Returns a standard HTTP Content-Type string.
 const char *GetHttpContentTypeString(HttpContentType type);
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_COMMON_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_COMMON_H_
diff --git a/http_fetcher.h b/http_fetcher.h
index 4a81cd5..78ceec6 100644
--- a/http_fetcher.h
+++ b/http_fetcher.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_FETCHER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_FETCHER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_FETCHER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_FETCHER_H_
 
 #include <deque>
 #include <string>
@@ -189,4 +189,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_FETCHER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HTTP_FETCHER_H_
diff --git a/hwid_override.h b/hwid_override.h
index 8f8dbc6..4d9bf9b 100644
--- a/hwid_override.h
+++ b/hwid_override.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H_
 
 #include <map>
 #include <string>
@@ -30,4 +30,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_HWID_OVERRIDE_H_
diff --git a/install_plan.cc b/install_plan.cc
index 1749cbe..4ae0de2 100644
--- a/install_plan.cc
+++ b/install_plan.cc
@@ -81,4 +81,3 @@
 }
 
 }  // namespace chromeos_update_engine
-
diff --git a/install_plan.h b/install_plan.h
index 29ce212..9090f0b 100644
--- a/install_plan.h
+++ b/install_plan.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_INSTALL_PLAN_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_INSTALL_PLAN_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_INSTALL_PLAN_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_INSTALL_PLAN_H_
 
 #include <string>
 #include <vector>
@@ -121,4 +121,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_INSTALL_PLAN_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_INSTALL_PLAN_H_
diff --git a/libcurl_http_fetcher.h b/libcurl_http_fetcher.h
index 35de32a..ff0275a 100644
--- a/libcurl_http_fetcher.h
+++ b/libcurl_http_fetcher.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H_
 
 #include <map>
 #include <string>
@@ -304,4 +304,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_LIBCURL_HTTP_FETCHER_H_
diff --git a/metadata.h b/metadata.h
index 72eb145..45f5752 100644
--- a/metadata.h
+++ b/metadata.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_METADATA_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_METADATA_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_METADATA_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_METADATA_H_
 
 #include "update_engine/delta_diff_generator.h"
 #include "update_engine/graph_types.h"
@@ -34,4 +34,4 @@
 
 };  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_METADATA_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_METADATA_H_
diff --git a/mock_file_writer.h b/mock_file_writer.h
index f2785cc..d662871 100644
--- a/mock_file_writer.h
+++ b/mock_file_writer.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_FILE_WRITER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_FILE_WRITER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_FILE_WRITER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_FILE_WRITER_H_
 
 #include "base/basictypes.h"
 #include "update_engine/file_writer.h"
@@ -56,4 +56,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_FILE_WRITER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_FILE_WRITER_H_
diff --git a/mock_gpio_handler.h b/mock_gpio_handler.h
index bee1cf6..985f138 100644
--- a/mock_gpio_handler.h
+++ b/mock_gpio_handler.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_GPIO_HANDLER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_GPIO_HANDLER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_GPIO_HANDLER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_GPIO_HANDLER_H_
 
 #include "gmock/gmock.h"
 #include "update_engine/gpio_handler.h"
@@ -17,4 +17,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_GPIO_HANDLER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_GPIO_HANDLER_H_
diff --git a/mock_hardware.h b/mock_hardware.h
index f24a4bf..37e50e7 100644
--- a/mock_hardware.h
+++ b/mock_hardware.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HARDWARE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HARDWARE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HARDWARE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HARDWARE_H_
 
 #include "fake_hardware.h"
 
@@ -79,4 +79,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HARDWARE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HARDWARE_H_
diff --git a/mock_http_fetcher.h b/mock_http_fetcher.h
index caa56d1..50e8043 100644
--- a/mock_http_fetcher.h
+++ b/mock_http_fetcher.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HTTP_FETCHER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HTTP_FETCHER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HTTP_FETCHER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HTTP_FETCHER_H_
 
 #include <vector>
 
@@ -139,4 +139,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HTTP_FETCHER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_HTTP_FETCHER_H_
diff --git a/mock_p2p_manager.h b/mock_p2p_manager.h
index 4d91765..353b904 100644
--- a/mock_p2p_manager.h
+++ b/mock_p2p_manager.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_P2P_MANAGER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_P2P_MANAGER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_P2P_MANAGER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_P2P_MANAGER_H_
 
 #include "fake_p2p_manager.h"
 
@@ -92,4 +92,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_P2P_MANAGER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_P2P_MANAGER_H_
diff --git a/mock_payload_state.h b/mock_payload_state.h
index 4e21a0f..8301adb 100644
--- a/mock_payload_state.h
+++ b/mock_payload_state.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_PAYLOAD_STATE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_PAYLOAD_STATE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_PAYLOAD_STATE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_PAYLOAD_STATE_H_
 
 #include "gmock/gmock.h"
 #include "update_engine/omaha_request_action.h"
@@ -57,4 +57,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_PAYLOAD_STATE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_PAYLOAD_STATE_H_
diff --git a/mock_system_state.cc b/mock_system_state.cc
index 13581f7..ddd294e 100644
--- a/mock_system_state.cc
+++ b/mock_system_state.cc
@@ -33,4 +33,3 @@
 }
 
 } // namespeace chromeos_update_engine
-
diff --git a/mock_system_state.h b/mock_system_state.h
index a6e764f..c24528e 100644
--- a/mock_system_state.h
+++ b/mock_system_state.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_SYSTEM_STATE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_SYSTEM_STATE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_SYSTEM_STATE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_SYSTEM_STATE_H_
 
 #include <gmock/gmock.h>
 
@@ -161,4 +161,4 @@
 
 } // namespeace chromeos_update_engine
 
-#endif // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_SYSTEM_STATE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MOCK_SYSTEM_STATE_H_
diff --git a/multi_range_http_fetcher.h b/multi_range_http_fetcher.h
index 652d0cb..029dcba 100644
--- a/multi_range_http_fetcher.h
+++ b/multi_range_http_fetcher.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H_
 
 #include <deque>
 #include <utility>
@@ -164,4 +164,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_MULTI_RANGE_HTTP_FETCHER_H_
diff --git a/omaha_hash_calculator.h b/omaha_hash_calculator.h
index bea3cc9..a45b14a 100644
--- a/omaha_hash_calculator.h
+++ b/omaha_hash_calculator.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_HASH_CALCULATOR_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_HASH_CALCULATOR_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_HASH_CALCULATOR_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_HASH_CALCULATOR_H_
 
 #include <string>
 #include <unistd.h>
@@ -99,4 +99,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_HASH_CALCULATOR_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_HASH_CALCULATOR_H_
diff --git a/omaha_request_action.cc b/omaha_request_action.cc
index b2d655e..941b511 100644
--- a/omaha_request_action.cc
+++ b/omaha_request_action.cc
@@ -1294,5 +1294,3 @@
 }
 
 }  // namespace chromeos_update_engine
-
-
diff --git a/omaha_request_action.h b/omaha_request_action.h
index f903d32..4b8b9f3 100644
--- a/omaha_request_action.h
+++ b/omaha_request_action.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_ACTION_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_ACTION_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_ACTION_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_ACTION_H_
 
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -277,4 +277,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_ACTION_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_ACTION_H_
diff --git a/omaha_request_params.h b/omaha_request_params.h
index f644775..e7113ba 100644
--- a/omaha_request_params.h
+++ b/omaha_request_params.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_PARAMS_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_PARAMS_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_PARAMS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_PARAMS_H_
 
 #include <string>
 
@@ -400,4 +400,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_PARAMS_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_PARAMS_H_
diff --git a/omaha_response.h b/omaha_response.h
index 4d380a7..e704ee0 100644
--- a/omaha_response.h
+++ b/omaha_response.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_H
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_H
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_H_
 
 #include <fcntl.h>
 #include <sys/stat.h>
@@ -84,4 +84,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_H
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_H_
diff --git a/omaha_response_handler_action.h b/omaha_response_handler_action.h
index db72c91..6179ba7 100644
--- a/omaha_response_handler_action.h
+++ b/omaha_response_handler_action.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_HANDLER_ACTION_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_HANDLER_ACTION_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_HANDLER_ACTION_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_HANDLER_ACTION_H_
 
 #include <string>
 
@@ -93,4 +93,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_HANDLER_ACTION_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_RESPONSE_HANDLER_ACTION_H_
diff --git a/p2p_manager.h b/p2p_manager.h
index e525746..0636e07 100644
--- a/p2p_manager.h
+++ b/p2p_manager.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_P2P_MANAGER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_P2P_MANAGER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_P2P_MANAGER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_P2P_MANAGER_H_
 
 #include <string>
 #include <vector>
@@ -167,4 +167,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_P2P_MANAGER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_P2P_MANAGER_H_
diff --git a/payload_signer.h b/payload_signer.h
index 95e6cc5..8b34f10 100644
--- a/payload_signer.h
+++ b/payload_signer.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_SIGNER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_SIGNER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_SIGNER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_SIGNER_H_
 
 #include <string>
 #include <vector>
@@ -154,4 +154,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_SIGNER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_SIGNER_H_
diff --git a/payload_state.h b/payload_state.h
index ad0f339..9e75a30 100644
--- a/payload_state.h
+++ b/payload_state.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_H_
 
 #include <base/time.h>
 #include <gtest/gtest_prod.h>  // for FRIEND_TEST
@@ -508,4 +508,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_H_
diff --git a/payload_state_interface.h b/payload_state_interface.h
index 5c67ba6..8742f23 100644
--- a/payload_state_interface.h
+++ b/payload_state_interface.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_INTERFACE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_INTERFACE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_INTERFACE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_INTERFACE_H_
 
 #include <string>
 
@@ -167,4 +167,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_INTERFACE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PAYLOAD_STATE_INTERFACE_H_
diff --git a/postinstall_runner_action.h b/postinstall_runner_action.h
index 0136ee2..fea0a39 100644
--- a/postinstall_runner_action.h
+++ b/postinstall_runner_action.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POSTINSTALL_RUNNER_ACTION_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POSTINSTALL_RUNNER_ACTION_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_POSTINSTALL_RUNNER_ACTION_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_POSTINSTALL_RUNNER_ACTION_H_
 
 #include <string>
 
@@ -60,4 +60,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POSTINSTALL_RUNNER_ACTION_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_POSTINSTALL_RUNNER_ACTION_H_
diff --git a/prefs.h b/prefs.h
index 55f721f..e119389 100644
--- a/prefs.h
+++ b/prefs.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_H_
 
 #include "base/file_path.h"
 #include "gtest/gtest_prod.h"  // for FRIEND_TEST
@@ -52,4 +52,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_H_
diff --git a/prefs_interface.h b/prefs_interface.h
index 0e7ad7d..a3676e4 100644
--- a/prefs_interface.h
+++ b/prefs_interface.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_INTERFACE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_INTERFACE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_INTERFACE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_INTERFACE_H_
 
 #include <string>
 
@@ -56,4 +56,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_INTERFACE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_INTERFACE_H_
diff --git a/prefs_mock.h b/prefs_mock.h
index a5492e2..5a56ba0 100644
--- a/prefs_mock.h
+++ b/prefs_mock.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_MOCK_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_MOCK_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_MOCK_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_MOCK_H_
 
 #include "gmock/gmock.h"
 #include "update_engine/constants.h"
@@ -28,4 +28,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_MOCK_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PREFS_MOCK_H_
diff --git a/proxy_resolver.h b/proxy_resolver.h
index fb96073..98cb53b 100644
--- a/proxy_resolver.h
+++ b/proxy_resolver.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PROXY_RESOLVER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PROXY_RESOLVER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_PROXY_RESOLVER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_PROXY_RESOLVER_H_
 
 
 #include <deque>
@@ -73,4 +73,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PROXY_RESOLVER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_PROXY_RESOLVER_H_
diff --git a/simple_key_value_store.h b/simple_key_value_store.h
index 24a1d75..b8d2da4 100644
--- a/simple_key_value_store.h
+++ b/simple_key_value_store.h
@@ -6,8 +6,8 @@
 // key value store. Each key/value pair is stored on its own line and
 // separated by the first '=' on the line.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H_
 
 #include <map>
 #include <string>
@@ -23,4 +23,4 @@
 }  // namespace simple_key_value_store
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_SIMPLE_KEY_VALUE_STORE_H_
diff --git a/subprocess.h b/subprocess.h
index c55b090..9e64806 100644
--- a/subprocess.h
+++ b/subprocess.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_SUBPROCESS_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_SUBPROCESS_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_SUBPROCESS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_SUBPROCESS_H_
 
 #include <map>
 #include <string>
@@ -104,4 +104,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_SUBPROCESS_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_SUBPROCESS_H_
diff --git a/tarjan.cc b/tarjan.cc
index b54a634..0e070ca 100644
--- a/tarjan.cc
+++ b/tarjan.cc
@@ -67,4 +67,3 @@
 }
 
 }  // namespace chromeos_update_engine
-
diff --git a/tarjan.h b/tarjan.h
index 1a80a95..53b0272 100644
--- a/tarjan.h
+++ b/tarjan.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_TARJAN_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_TARJAN_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_TARJAN_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_TARJAN_H_
 
 // This is an implemenation of Tarjan's algorithm which finds all
 // Strongly Connected Components in a graph.
@@ -36,4 +36,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_TARJAN_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_TARJAN_H_
diff --git a/terminator.h b/terminator.h
index 97c9d7f..e536d38 100644
--- a/terminator.h
+++ b/terminator.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_TERMINATOR_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_TERMINATOR_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_TERMINATOR_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_TERMINATOR_H_
 
 #include <signal.h>
 
@@ -50,4 +50,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_TERMINATOR_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_TERMINATOR_H_
diff --git a/test_utils.h b/test_utils.h
index 32ae19d..0ca4639 100644
--- a/test_utils.h
+++ b/test_utils.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_TEST_UTILS_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_TEST_UTILS_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_TEST_UTILS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_TEST_UTILS_H_
 
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -290,4 +290,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_TEST_UTILS_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_TEST_UTILS_H_
diff --git a/topological_sort.h b/topological_sort.h
index d4a5446..545d6d6 100644
--- a/topological_sort.h
+++ b/topological_sort.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_TOPOLOGICAL_SORT_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_TOPOLOGICAL_SORT_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_TOPOLOGICAL_SORT_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_TOPOLOGICAL_SORT_H_
 
 
 #include <vector>
@@ -27,4 +27,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_TOPOLOGICAL_SORT_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_TOPOLOGICAL_SORT_H_
diff --git a/udev_interface.h b/udev_interface.h
index c241567..4b45d4c 100644
--- a/udev_interface.h
+++ b/udev_interface.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UDEV_INTERFACE_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UDEV_INTERFACE_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UDEV_INTERFACE_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UDEV_INTERFACE_H_
 
 #include <libudev.h>
 
@@ -193,5 +193,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UDEV_INTERFACE_H__
-
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UDEV_INTERFACE_H_
diff --git a/update_attempter.h b/update_attempter.h
index d93c049..216d3c1 100644
--- a/update_attempter.h
+++ b/update_attempter.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H_
 
 #include <time.h>
 
@@ -447,4 +447,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_H_
diff --git a/update_attempter_mock.h b/update_attempter_mock.h
index 5b57dbc..af1b7c1 100644
--- a/update_attempter_mock.h
+++ b/update_attempter_mock.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_MOCK_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_MOCK_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_MOCK_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_MOCK_H_
 
 #include <gmock/gmock.h>
 
@@ -30,4 +30,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_MOCK_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_ATTEMPTER_MOCK_H_
diff --git a/update_check_scheduler.h b/update_check_scheduler.h
index 9a5faa5..c7b64c6 100644
--- a/update_check_scheduler.h
+++ b/update_check_scheduler.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_CHECK_SCHEDULER_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_CHECK_SCHEDULER_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_CHECK_SCHEDULER_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_CHECK_SCHEDULER_H_
 
 #include <base/basictypes.h>
 #include <glib.h>
@@ -139,4 +139,4 @@
 
 }  // namespace chromeos_update_engine
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CHECK_SCHEDULER_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UPDATE_CHECK_SCHEDULER_H_
diff --git a/utils.h b/utils.h
index a84f512..f404653 100644
--- a/utils.h
+++ b/utils.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__
-#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__
+#ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H_
+#define CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H_
 
 #include <algorithm>
 #include <errno.h>
@@ -609,4 +609,4 @@
 
 
 
-#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H__
+#endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_UTILS_H_