Disable MSE_ClearKey/EncryptedMediaTest.Playback_VideoOnly_WebM/0 as its failing often.

chrome/browser/media/encrypted_media_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/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/win/windows_version.h"
 #include "chrome/browser/media/media_browsertest.h"
@@ skipping 508 matching lines @@
 }
 
 IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, Playback_AudioClearVideo_WebM) {
   TestSimplePlayback("bear-320x240-av_enc-a.webm", kWebMAudioVideo);
 }
 
 IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, Playback_VideoAudio_WebM) {
   TestSimplePlayback("bear-320x240-av_enc-av.webm", kWebMAudioVideo);
 }
 
-IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, Playback_VideoOnly_WebM) {
+// http://crbug.com/402766
+IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, DISABLED_Playback_VideoOnly_WebM) {
   TestSimplePlayback("bear-320x240-v_enc-v.webm", kWebMVideoOnly);
 }
 
 IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, Playback_VideoClearAudio_WebM) {
   TestSimplePlayback("bear-320x240-av_enc-v.webm", kWebMAudioVideo);
 }
 
 // http://crbug.com/402766
 IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, DISABLED_Playback_VP9Video_WebM) {
   TestSimplePlayback("bear-320x240-v-vp9_enc-v.webm", kWebMVP9VideoOnly);
@@ skipping 121 matching lines @@
                         "bear-320x240-v_enc-v.webm",
                         kWebMVideoOnly,
                         kExternalClearKeyKeySystem,
                         SRC,
                         PREFIXED,
                         kUnknownSession,
                         false,
                         kEmeKeyError);
 }
 #endif  // defined(ENABLE_PEPPER_CDMS)