Removed custom FFmpegLock. Removed ffmpeg headers from third_party/ffmpeg/include.

media/ffmpeg/ffmpeg_common.h

Index: media/ffmpeg/ffmpeg_common.h
diff --git a/media/ffmpeg/ffmpeg_common.h b/media/ffmpeg/ffmpeg_common.h
index 9be245ff1d418f1034c21ec33f3e57d1bdb431a3..4b600460b50722458ef1a1681f626e7f293422ce 100644
--- a/media/ffmpeg/ffmpeg_common.h
+++ b/media/ffmpeg/ffmpeg_common.h
@@ -19,34 +19,14 @@ extern "C" {
 // Temporarily disable possible loss of data warning.
 // TODO(scherkus): fix and upstream the compiler warnings.
 MSVC_PUSH_DISABLE_WARNING(4244);
-#include "third_party/ffmpeg/include/libavcodec/avcodec.h"
-#include "third_party/ffmpeg/include/libavformat/avformat.h"
-#include "third_party/ffmpeg/include/libavutil/log.h"
+#include "third_party/ffmpeg/source/patched-ffmpeg-mt/libavcodec/avcodec.h"
+#include "third_party/ffmpeg/source/patched-ffmpeg-mt/libavformat/avformat.h"
+#include "third_party/ffmpeg/source/patched-ffmpeg-mt/libavutil/log.h"
 MSVC_POP_WARNING();
 }  // extern "C"
 
 namespace media {
 
-// FFmpegLock is used to serialize calls to avcodec_open(), avcodec_close(),
-// and av_find_stream_info() for an entire process because for whatever reason
-// it does Very Bad Things to other FFmpeg instances.
-//
-// TODO(scherkus): track down and upstream a fix to FFmpeg, if possible.
-class FFmpegLock : public Singleton<FFmpegLock> {
- public:
-  Lock& lock();
-
- private:
-  // Only allow Singleton to create and delete FFmpegLock.
-  friend struct DefaultSingletonTraits<FFmpegLock>;
-  FFmpegLock();
-  virtual ~FFmpegLock();
-
-  Lock lock_;
-  DISALLOW_COPY_AND_ASSIGN(FFmpegLock);
-};
-
-
 // Wraps FFmpeg's av_free() in a class that can be passed as a template argument
 // to scoped_ptr_malloc.
 class ScopedPtrAVFree {