Disable flaky test ThumbnailDiskStorageTest#testRemoveAllThumbnailsWithSameContentId

TBR=qinmin@chromium.org
BUG=778829
NOTRY=true

Change-Id: I7f95b097012f6bb5b46458c43e71edf4a5861c8c
Reviewed-on: https://chromium-review.googlesource.com/776127Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517227}

chrome/android/javatests/src/org/chromium/chrome/browser/widget/ThumbnailDiskStorageTest.java

@@ -17,6 +17,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 
 import org.chromium.base.ThreadUtils;
+import org.chromium.base.test.util.DisabledTest;
 import org.chromium.base.test.util.UrlUtils;
 import org.chromium.chrome.test.ChromeJUnit4ClassRunner;
 import org.chromium.content.browser.test.util.Criteria;
@@ -274,6 +275,7 @@ public class ThumbnailDiskStorageTest {
      * Verify that removeFromDisk removes all thumbnails with the same content ID but different
      * sizes.
      */
+    @DisabledTest(message = "crbug.com/778829")
     @Test
     @SmallTest
     public void testRemoveAllThumbnailsWithSameContentId() throws Throwable {