Disable flaky media unit tests.

media/base/android/media_codec_decoder_unittest.cc

Index: media/base/android/media_codec_decoder_unittest.cc
diff --git a/media/base/android/media_codec_decoder_unittest.cc b/media/base/android/media_codec_decoder_unittest.cc
index ea0ffb35f3634d70e493905b3c770517ecf0866c..63aaaf7d7b6a079d50633391fd05048c3197d005 100644
--- a/media/base/android/media_codec_decoder_unittest.cc
+++ b/media/base/android/media_codec_decoder_unittest.cc
@@ -505,7 +505,7 @@ TEST_F(MediaCodecDecoderTest, AudioStartWithoutConfigure) {
 }
 
 // http://crbug.com/518900
-TEST_F(MediaCodecDecoderTest, AudioPlayTillCompletion) {
+TEST_F(MediaCodecDecoderTest, DISABLED_AudioPlayTillCompletion) {
   SKIP_TEST_IF_MEDIA_CODEC_BRIDGE_IS_NOT_AVAILABLE();
 
   DVLOG(0) << "AudioPlayTillCompletion started";