Remove browser-side tracking of accelerated compositing

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <QuartzCore/QuartzCore.h>
 
 #include "base/basictypes.h"
@@ skipping 1192 matching lines @@
         src_pixel_rect.width(), src_pixel_rect.height());
     target_canvas.drawBitmapRectToRect(
         source_bitmap,
         &src_pixel_skrect,
         SkRect::MakeXYWH(0, 0, dst_pixel_size.width(), dst_pixel_size.height()),
         NULL,
         SkCanvas::kNone_DrawBitmapRectFlag);
 
     ignore_result(scoped_callback_runner.Release());
     callback.Run(true, target_bitmap);
+  } else {
+    callback.Run(false, SkBitmap());

[danakj, 2014/05/12 17:37:58]

should we NOTREACHED? or is this a valid case

[piman, 2014/05/13 20:25:40]

Won't we get here if we CopyFromCompositingSurface before we received any frame?

[danakj, 2014/05/13 21:23:43]

Only if you didn't check IsSurfaceAvailableForCopy() first, which I would expect
us to.

But maybe not, RendererOverridesHandler::InnerSwapCompositorFrame seems to not
check first. Tho maybe it doesn't need to.

And I guess RenderWidgetHostImpl::CopyFromBackingStore doesn't check first. Huh.

   }
 }
 
 void RenderWidgetHostViewMac::CopyFromCompositingSurfaceToVideoFrame(
       const gfx::Rect& src_subrect,
       const scoped_refptr<media::VideoFrame>& target,
       const base::Callback<void(bool)>& callback) {
   base::ScopedClosureRunner scoped_callback_runner(base::Bind(callback, false));
-  if (!render_widget_host_->is_accelerated_compositing_active() ||
-      !compositing_iosurface_ ||
+  if (!compositing_iosurface_ ||
       !compositing_iosurface_->HasIOSurface())
     return;
 
   if (!target.get()) {
     NOTREACHED();
     return;
   }
 
   if (target->format() != media::VideoFrame::YV12 &&
       target->format() != media::VideoFrame::I420) {
     NOTREACHED();
     return;
   }
 
   if (src_subrect.IsEmpty())
     return;
 
   ignore_result(scoped_callback_runner.Release());
   compositing_iosurface_->CopyToVideoFrame(
       GetScaledOpenGLPixelRect(src_subrect),
       target,
       callback);
 }
 
 bool RenderWidgetHostViewMac::CanCopyToVideoFrame() const {
   return (!software_frame_manager_->HasCurrentFrame() &&
-          render_widget_host_->is_accelerated_compositing_active() &&
           compositing_iosurface_ &&
           compositing_iosurface_->HasIOSurface());
 }
 
 bool RenderWidgetHostViewMac::CanSubscribeFrame() const {
   return !software_frame_manager_->HasCurrentFrame();
 }
 
 void RenderWidgetHostViewMac::BeginFrameSubscription(
     scoped_ptr<RenderWidgetHostViewFrameSubscriber> subscriber) {
@@ skipping 550 matching lines @@
       !render_widget_host_->is_hidden());
 
   // Notify observers, tab capture observers in particular, that a new software
   // frame has come in.
   NotificationService::current()->Notify(
       NOTIFICATION_RENDER_WIDGET_HOST_DID_UPDATE_BACKING_STORE,
       Source<RenderWidgetHost>(render_widget_host_),
       NotificationService::NoDetails());
 }
 
-void RenderWidgetHostViewMac::OnAcceleratedCompositingStateChange() {
-}
-
 void RenderWidgetHostViewMac::AcceleratedSurfaceInitialized(int host_id,
                                                             int route_id) {
 }
 
 void RenderWidgetHostViewMac::GetScreenInfo(blink::WebScreenInfo* results) {
   *results = GetWebScreenInfo(GetNativeView());
 }
 
 gfx::Rect RenderWidgetHostViewMac::GetBoundsInRootWindow() {
   // TODO(shess): In case of !window, the view has been removed from
@@ skipping 2446 matching lines @@
 }
 
 - (void)disableRendering {
   // Disable the fade-out animation as the layer is removed.
   ScopedCAActionDisabler disabler;
   [self removeFromSuperlayer];
   renderWidgetHostView_ = nil;
 }
 
 @end  // implementation SoftwareLayer