Run VDA::Decode on GPU IO thread if VDA supports it.

content/common/gpu/media/exynos_video_decode_accelerator.cc

Index: content/common/gpu/media/exynos_video_decode_accelerator.cc
diff --git a/content/common/gpu/media/exynos_video_decode_accelerator.cc b/content/common/gpu/media/exynos_video_decode_accelerator.cc
index 677df9c350470545a468614d8b3e08f8b7fe94bd..44c40c27c3b2cb2f73475dec447e6babc51dfa5d 100644
--- a/content/common/gpu/media/exynos_video_decode_accelerator.cc
+++ b/content/common/gpu/media/exynos_video_decode_accelerator.cc
@@ -205,8 +205,10 @@ ExynosVideoDecodeAccelerator::ExynosVideoDecodeAccelerator(
     EGLDisplay egl_display,
     EGLContext egl_context,
     Client* client,
-    const base::Callback<bool(void)>& make_context_current)
+    const base::Callback<bool(void)>& make_context_current,
+    const scoped_refptr<base::MessageLoopProxy>& io_message_loop_proxy)
     : child_message_loop_proxy_(base::MessageLoopProxy::current()),
+      io_message_loop_proxy_(io_message_loop_proxy),
       weak_this_(base::AsWeakPtr(this)),
       client_ptr_factory_(client),
       client_(client_ptr_factory_.GetWeakPtr()),
@@ -415,7 +417,7 @@ void ExynosVideoDecodeAccelerator::Decode(
     const media::BitstreamBuffer& bitstream_buffer) {
   DVLOG(1) << "Decode(): input_id=" << bitstream_buffer.id()
            << ", size=" << bitstream_buffer.size();
-  DCHECK(child_message_loop_proxy_->BelongsToCurrentThread());
+  DCHECK(io_message_loop_proxy_->BelongsToCurrentThread());
 
   scoped_ptr<BitstreamBufferRef> bitstream_record(new BitstreamBufferRef(
       client_, child_message_loop_proxy_,