AU: Change test http server port from 8080 to 8088.

This allows developers to run unit tests while the dev server is running. Also
remove obsole test_http_server.py.

BUG=8889
TEST=unit tests while dev server is running.

Change-Id: Iaf0ff92edbb959d93bd206c0007455f637682e2c

Review URL: http://codereview.chromium.org/4667002
diff --git a/subprocess_unittest.cc b/subprocess_unittest.cc
index 10dccbe..679f85c 100644
--- a/subprocess_unittest.cc
+++ b/subprocess_unittest.cc
@@ -25,7 +25,7 @@
 };
 
 namespace {
-const int kLocalHttpPort = 8080;
+const int kLocalHttpPort = 8088;
 
 void Callback(int return_code, void *p) {
   EXPECT_EQ(256, return_code);