gpu video: optimize HW video to SW canvas and implement it for WebRTC.

media/filters/gpu_video_decoder.cc

Index: media/filters/gpu_video_decoder.cc
diff --git a/media/filters/gpu_video_decoder.cc b/media/filters/gpu_video_decoder.cc
index 6601db88ab377f1fbc999930d125e37f5bcdb36a..5bbd071673812f5aaea77d70c46aa187817b2ad5 100644
--- a/media/filters/gpu_video_decoder.cc
+++ b/media/filters/gpu_video_decoder.cc
@@ -13,7 +13,6 @@
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
-#include "base/synchronization/waitable_event.h"
 #include "base/task_runner_util.h"
 #include "gpu/command_buffer/common/mailbox_holder.h"
 #include "media/base/bind_to_current_loop.h"
@@ -385,33 +384,6 @@ void GpuVideoDecoder::DismissPictureBuffer(int32 id) {
   // Postpone deletion until after it's returned to us.
 }
 
-static void ReadPixelsSyncInner(
-    const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories,
-    uint32 texture_id,
-    const gfx::Rect& visible_rect,
-    const SkBitmap& pixels,
-    base::WaitableEvent* event) {
-  factories->ReadPixels(texture_id, visible_rect, pixels);

[dshwang, 2015/01/14 20:32:13]

it's executed in media thread.

-  event->Signal();
-}
-
-static void ReadPixelsSync(
-    const scoped_refptr<media::GpuVideoAcceleratorFactories>& factories,
-    uint32 texture_id,
-    const gfx::Rect& visible_rect,
-    const SkBitmap& pixels) {
-  base::WaitableEvent event(true, false);

[dshwang, 2015/01/14 20:32:13]

wait Blink thread until the job getting done in media thread

-  if (!factories->GetTaskRunner()->PostTask(FROM_HERE,
-                                            base::Bind(&ReadPixelsSyncInner,
-                                                       factories,
-                                                       texture_id,
-                                                       visible_rect,
-                                                       pixels,
-                                                       &event)))
-    return;
-  event.Wait();
-}
-
 void GpuVideoDecoder::PictureReady(const media::Picture& picture) {
   DVLOG(3) << "PictureReady()";
   DCheckGpuVideoAcceleratorFactoriesTaskRunnerIsCurrent();
@@ -450,16 +422,10 @@ void GpuVideoDecoder::PictureReady(const media::Picture& picture) {
   scoped_refptr<VideoFrame> frame(VideoFrame::WrapNativeTexture(
       make_scoped_ptr(new gpu::MailboxHolder(
           pb.texture_mailbox(), decoder_texture_target_, 0 /* sync_point */)),
-      BindToCurrentLoop(base::Bind(&GpuVideoDecoder::ReleaseMailbox,
-                                   weak_factory_.GetWeakPtr(),
-                                   factories_,
-                                   picture.picture_buffer_id(),
-                                   pb.texture_id())),
-      pb.size(),
-      visible_rect,
-      natural_size,
-      timestamp,
-      base::Bind(&ReadPixelsSync, factories_, pb.texture_id(), visible_rect)));
+      BindToCurrentLoop(base::Bind(
+          &GpuVideoDecoder::ReleaseMailbox, weak_factory_.GetWeakPtr(),
+          factories_, picture.picture_buffer_id(), pb.texture_id())),
+      pb.size(), visible_rect, natural_size, timestamp));
   CHECK_GT(available_pictures_, 0);
   --available_pictures_;
   bool inserted =