Disable crashing media tests on Mac.

chrome/browser/media/encrypted_media_browsertest.cc

Index: chrome/browser/media/encrypted_media_browsertest.cc
diff --git a/chrome/browser/media/encrypted_media_browsertest.cc b/chrome/browser/media/encrypted_media_browsertest.cc
index 113717636024bd24c12a057765b614e40a4520f9..326f4cdb734ffe3ae2482a4e35b4a442ef101478 100644
--- a/chrome/browser/media/encrypted_media_browsertest.cc
+++ b/chrome/browser/media/encrypted_media_browsertest.cc
@@ -523,7 +523,13 @@ IN_PROC_BROWSER_TEST_P(EncryptedMediaTest, FrameSizeChangeVideo) {
 }
 
 #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.";