Disable WebViewTest.ClearDataCache on Windows as it's flakily failing.

chrome/browser/apps/guest_view/web_view_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 "base/path_service.h"
 #include "base/process/process.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/apps/app_browsertest_util.h"
@@ skipping 2331 matching lines @@
   if (base::win::GetVersion() <= base::win::VERSION_XP)
     return;
 #endif
 
   ASSERT_TRUE(StartEmbeddedTestServer());  // For serving guest pages.
   ASSERT_TRUE(RunPlatformAppTestWithArg(
       "platform_apps/web_view/common", "cleardata"))
           << message_;
 }
 
-IN_PROC_BROWSER_TEST_F(WebViewTest, ClearDataCache) {
+#if defined(OS_WIN)
+// Test is disabled on Windows because it fails often (~9% time)
+// http://crbug.com/489088
+#define MAYBE_ClearDataCache DISABLED_ClearDataCache
+#else
+#define MAYBE_ClearDataCache ClearDataCache
+#endif
+IN_PROC_BROWSER_TEST_F(WebViewTest, MAYBE_ClearDataCache) {
   TestHelper("testClearCache", "web_view/clear_data_cache", NEEDS_TEST_SERVER);
 }
 
 IN_PROC_BROWSER_TEST_F(WebViewTest, ConsoleMessage) {
   ASSERT_TRUE(RunPlatformAppTestWithArg(
       "platform_apps/web_view/common", "console_messages"))
           << message_;
 }
 
 IN_PROC_BROWSER_TEST_F(WebViewTest, DownloadPermission) {
@@ skipping 341 matching lines @@
 // This test verifies that the allowtransparency attribute properly propagates
 IN_PROC_BROWSER_TEST_F(WebViewTest, AllowTransparencyAndAllowScalingPropagate) {
   LoadAppWithGuest("web_view/simple");
 
   ASSERT_TRUE(GetGuestWebContents());
   extensions::WebViewGuest* guest =
       extensions::WebViewGuest::FromWebContents(GetGuestWebContents());
   ASSERT_TRUE(guest->allow_transparency());
   ASSERT_TRUE(guest->allow_scaling());
 }