Set default updater URL and version per platform.

Chrome OS and Brillo devices require different production update URL
and updater string ID sent to Omaha. This patch moves these constants
to a platform-dependent file with the definition of the constants.

Bug: brillo:587,brillo:588
Test: FEATURES=test emerge-link update_engine; `mma`; deployed on a dragonboard.

Change-Id: Ibe3b30c32c2fb2caf3ed10a4198272dc13a44d12
diff --git a/platform_constants.h b/platform_constants.h
new file mode 100644
index 0000000..9f8778e
--- /dev/null
+++ b/platform_constants.h
@@ -0,0 +1,39 @@
+//
+// Copyright (C) 2015 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef UPDATE_ENGINE_PLATFORM_CONSTANTS_H_
+#define UPDATE_ENGINE_PLATFORM_CONSTANTS_H_
+
+namespace chromeos_update_engine {
+namespace constants {
+
+// The default URL used by all products when running in normal mode. The AUTest
+// URL is used when testing normal images against the alternative AUTest server.
+// Note that the URL can be override in run-time in certain cases.
+extern const char kOmahaDefaultProductionURL[];
+extern const char kOmahaDefaultAUTestURL[];
+
+// Our product name used in Omaha. This value must match the one configured in
+// the server side and is sent on every request.
+extern const char kOmahaUpdaterID[];
+
+// The name of the platform as sent to Omaha.
+extern const char kOmahaPlatformName[];
+
+}  // namespace constants
+}  // namespace chromeos_update_engine
+
+#endif  // UPDATE_ENGINE_PLATFORM_CONSTANTS_H_