Disable PlatformAppBrowserTest.Messaging on Windows as its flaky.

chrome/browser/apps/app_browsertest.cc

 // Copyright 2013 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 "apps/app_window.h"
 #include "apps/app_window_registry.h"
 #include "apps/launcher.h"
 #include "apps/ui/native_app_window.h"
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 1033 matching lines @@
   app_loaded_observer.Wait();
   ASSERT_TRUE(should_install.seen());
 
   ExtensionTestMessageListener launched_listener("Launched", false);
   OpenApplication(AppLaunchParams(
       browser()->profile(), extension, LAUNCH_CONTAINER_NONE, NEW_WINDOW));
 
   ASSERT_TRUE(launched_listener.WaitUntilSatisfied());
 }
 
-IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, Messaging) {
+// Fails on Win7. http://crbug.com/171450
+#if defined(OS_WIN)
+#define MAYBE_Messaging DISABLED_Messaging
+#else
+#define MAYBE_Messaging Messaging
+#endif
+IN_PROC_BROWSER_TEST_F(PlatformAppBrowserTest, MAYBE_Messaging) {
   ExtensionApiTest::ResultCatcher result_catcher;
   LoadAndLaunchPlatformApp("messaging/app2", "Ready");
   LoadAndLaunchPlatformApp("messaging/app1", "Launched");
   EXPECT_TRUE(result_catcher.GetNextResult());
 }
 
 // TODO(linux_aura) http://crbug.com/163931
 #if defined(OS_LINUX) && !defined(OS_CHROMEOS) && defined(USE_AURA)
 #define MAYBE_WebContentsHasFocus DISABLED_WebContentsHasFocus
 #else
@@ skipping 219 matching lines @@
         LoadAndLaunchPlatformApp("reinstall_data_cleanup", "Launched");
     ASSERT_TRUE(extension);
     ASSERT_EQ(extension_id, extension->id());
 
     ExtensionApiTest::ResultCatcher result_catcher;
     EXPECT_TRUE(result_catcher.GetNextResult());
   }
 }
 
 }  // namespace extensions