Reduce flakiness in chrome_frame_tests.exe by having each run in a clean environment.

chrome_frame/test/chrome_frame_automation_mock.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome_frame/test/chrome_frame_automation_mock.h"
 #include "chrome_frame/test/chrome_frame_test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 const int kLongWaitTimeout = 25 * 1000;
-const int kShortWaitTimeout = 5 * 1000;
 
-// This test has been marked as flaky as it randomly times out on the CF
-// builders
-// http://code.google.com/p/chromium/issues/detail?id=81479
-TEST(ChromeFrame, DISABLED_Launch) {
+TEST(ChromeFrame, Launch) {
   MessageLoopForUI loop;
   AutomationMockLaunch mock_launch(&loop, kLongWaitTimeout);
 
   loop.PostDelayedTask(FROM_HERE, MessageLoop::QuitClosure(), kLongWaitTimeout);
 
   mock_launch.Navigate("about:blank");
   loop.RunWithDispatcher(NULL);
   EXPECT_TRUE(mock_launch.launch_result());
 }
 
@@ skipping 12 matching lines @@
   MessageLoopForUI loop;
   AutomationMockPostMessage mock_postmessage(&loop, kLongWaitTimeout);
 
   loop.PostDelayedTask(FROM_HERE, MessageLoop::QuitClosure(), kLongWaitTimeout);
 
   mock_postmessage.NavigateRelativeFile(L"postmessage_basic_frame.html");
   loop.RunWithDispatcher(NULL);
   EXPECT_FALSE(mock_postmessage.postmessage_result());
 }
 
-// Marking this test as flaky as it fails randomly on the CF builders.
-// http://code.google.com/p/chromium/issues/detail?id=81479
-TEST(ChromeFrame, DISABLED_RequestStart) {
+TEST(ChromeFrame, RequestStart) {
   MessageLoopForUI loop;
   AutomationMockHostNetworkRequestStart mock_request_start(&loop,
                                                            kLongWaitTimeout);
 
   loop.PostDelayedTask(FROM_HERE, MessageLoop::QuitClosure(), kLongWaitTimeout);
 
   mock_request_start.NavigateRelative(L"postmessage_basic_frame.html");
   loop.RunWithDispatcher(NULL);
   EXPECT_TRUE(mock_request_start.request_start_result());
 }