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

BUG=489088
Test=None, internal change.

Review URL: https://codereview.chromium.org/1146713002

Cr-Commit-Position: refs/heads/master@{#330454}

chrome/browser/apps/guest_view/web_view_browsertest.cc

@@ -2349,7 +2349,14 @@ IN_PROC_BROWSER_TEST_F(WebViewTest, 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);
 }