Android: enable/disable WebRTC HW H264 with a flag.

media/base/android/media_codec_util.h

Index: media/base/android/media_codec_util.h
diff --git a/media/base/android/media_codec_util.h b/media/base/android/media_codec_util.h
index 09e5ac84d1de63908e321f4a74bd4191aac6deed..59f07467bc0e3143b4a6dde4051531c3d6db7856 100644
--- a/media/base/android/media_codec_util.h
+++ b/media/base/android/media_codec_util.h
@@ -77,6 +77,9 @@ class MEDIA_EXPORT MediaCodecUtil {
   // Indicates if the vp9 decoder is available on this device.
   static bool IsVp9DecoderAvailable();
 
+  // Indicates if the h264 encoder is available on this device.
+  static bool IsH264EncoderAvailable();
+
   // Indicates if SurfaceView and MediaCodec work well together on this device.
   static bool IsSurfaceViewOutputSupported();