Mark some sync tests as flaky.

chrome/test/live_sync/two_client_live_bookmarks_sync_test.cc

 // Copyright (c) 2011 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/rand_util.h"
 #include "base/stringprintf.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sync/profile_sync_service_harness.h"
 #include "chrome/test/live_sync/live_bookmarks_sync_test.h"
 
@@ skipping 105 matching lines @@
                        SC_AddFirstBMWithoutFavicon) {
   ASSERT_TRUE(SetupSync()) << "SetupSync() failed.";
   ASSERT_TRUE(AllModelsMatchVerifier());
 
   ASSERT_TRUE(AddURL(0, kGenericURLTitle, GURL(kGenericURL)) != NULL);
   ASSERT_TRUE(GetClient(0)->AwaitMutualSyncCycleCompletion(GetClient(1)));
   ASSERT_TRUE(AllModelsMatchVerifier());
 }
 
 // Test Scribe ID - 370489.
+// TODO(rsimha): See http://crbug.com/78840.
 IN_PROC_BROWSER_TEST_F(TwoClientLiveBookmarksSyncTest,
-                       SC_AddFirstBMWithFavicon) {
+                       FLAKY_SC_AddFirstBMWithFavicon) {
   ASSERT_TRUE(SetupSync()) << "SetupSync() failed.";
   ASSERT_TRUE(AllModelsMatchVerifier());
 
   const BookmarkNode* bookmark = AddURL(0, kGenericURLTitle, GURL(kGenericURL));
   ASSERT_TRUE(bookmark != NULL);
   ASSERT_TRUE(GetClient(0)->AwaitMutualSyncCycleCompletion(GetClient(1)));
   SetFavicon(0, bookmark, GenericFavicon());
   ASSERT_TRUE(GetClient(0)->AwaitMutualSyncCycleCompletion(GetClient(1)));
   ASSERT_TRUE(AllModelsMatchVerifier());
 }
@@ skipping 1334 matching lines @@
   }
 
   ASSERT_TRUE(SetupSync()) << "SetupSync() failed.";
   ASSERT_TRUE(AwaitQuiescence());
   ASSERT_TRUE(AllModelsMatch());
 
   for (int i = 1; i < 5 ; ++i) {
     ASSERT_TRUE(CountBookmarksWithTitlesMatching(1, IndexedURLTitle(i)) == i);
   }
 }