Drop idle MediaCodec instances after a few seconds within AVDA.

media/gpu/android_video_decode_accelerator.h

Index: media/gpu/android_video_decode_accelerator.h
diff --git a/media/gpu/android_video_decode_accelerator.h b/media/gpu/android_video_decode_accelerator.h
index fd99ebc0ff8a7ca2e74a4bd047c212cbbece37d8..4c4c5e82bb73049f8d043f8b70d23660702ab4df 100644
--- a/media/gpu/android_video_decode_accelerator.h
+++ b/media/gpu/android_video_decode_accelerator.h
@@ -371,6 +371,10 @@ class MEDIA_GPU_EXPORT AndroidVideoDecodeAccelerator
   // have safer versions elsewhere.
   bool IsMediaCodecSoftwareDecodingForbidden() const;
 
+  // Closes idle MediaCodec instances if no Decode() call is received within a
+  // few seconds.
+  void CloseIdleCodec();
+
   // Used to DCHECK that we are called on the correct thread.
   base::ThreadChecker thread_checker_;
 
@@ -484,6 +488,11 @@ class MEDIA_GPU_EXPORT AndroidVideoDecodeAccelerator
 
   OnDestroyingSurfaceCallback on_destroying_surface_cb_;
 
+  // Timer used to destroy the MediaCodec if no Decode() call is received after
+  // some period of idle activity. This prevents older devices from falling over
+  // when too many MediaCodec instances are outstanding.
+  base::OneShotTimer no_decode_timeout_;
+
   // WeakPtrFactory for posting tasks back to |this|.
   base::WeakPtrFactory<AndroidVideoDecodeAccelerator> weak_this_factory_;