Disable crashing media tests on Mac.

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 <memory>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 505 matching lines @@
     return;
 #endif
   if (!IsPlayBackPossible(CurrentKeySystem())) {
     DVLOG(0) << "Skipping test - FrameSizeChange test requires video playback.";
     return;
   }
   TestFrameSizeChange();
 }
 
 #if defined(USE_PROPRIETARY_CODECS)
-IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, Playback_VideoOnly_MP4) {
+// Crashes on Mac only.  http://crbug.com/621857
+#if defined(OS_MACOSX)
+#define MAYBE_Playback_VideoOnly_MP4 DISABLED_Playback_VideoOnly_MP4
+#else
+#define MAYBE_Playback_VideoOnly_MP4 Playback_VideoOnly_MP4
+#endif
+IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, MAYBE_Playback_VideoOnly_MP4) {
   // MP4 without MSE is not support yet, http://crbug.com/170793.
   if (CurrentSourceType() != MSE) {
     DVLOG(0) << "Skipping test; Can only play MP4 encrypted streams by MSE.";
     return;
   }
   TestSimplePlayback("bear-640x360-v_frag-cenc.mp4", kMP4VideoOnly);
 }
 
 IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, Playback_AudioOnly_MP4) {
   // MP4 without MSE is not support yet, http://crbug.com/170793.
@@ skipping 88 matching lines @@
 
 IN_PROC_BROWSER_TEST_F(ECKEncryptedMediaTest, LoadLoadableSession) {
   TestPlaybackCase(kLoadableSession, kEnded);
 }
 
 IN_PROC_BROWSER_TEST_F(ECKEncryptedMediaTest, LoadUnknownSession) {
   TestPlaybackCase(kUnknownSession, kEmeSessionNotFound);
 }
 
 #endif  // defined(ENABLE_PEPPER_CDMS)