Clean up GPU back-pressure with remote CALayers

content/browser/compositor/browser_compositor_ca_layer_tree_mac.mm

 // Copyright 2014 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/compositor/browser_compositor_ca_layer_tree_mac.h"
 
 #include <map>
 
 #include "base/debug/trace_event.h"
 #include "base/lazy_instance.h"
@@ skipping 98 matching lines @@
     const gfx::Size& dip_size) const {
   return last_swap_size_dip_ == dip_size;
 }
 
 int BrowserCompositorCALayerTreeMac::GetRendererID() const {
   if (io_surface_layer_)
     return [io_surface_layer_ rendererID];
   return 0;
 }
 
+bool BrowserCompositorCALayerTreeMac::IsRendererThrottlingDisabled() const {
+  if (client_)
+    return client_->BrowserCompositorViewShouldAckImmediately();
+  return false;
+}
+
 void BrowserCompositorCALayerTreeMac::BeginPumpingFrames() {
   [io_surface_layer_ beginPumpingFrames];
 }
 
 void BrowserCompositorCALayerTreeMac::EndPumpingFrames() {
   [io_surface_layer_ endPumpingFrames];
 }
 
 void BrowserCompositorCALayerTreeMac::GotAcceleratedFrame(
     uint64 surface_handle, int output_surface_id,
@@ skipping 232 matching lines @@
       g_widget_to_internals_map.Pointer()->find(widget);
   // This can end up being accessed after the underlying widget has been
   // destroyed, but while the ui::Compositor is still being destroyed.
   // Return NULL in these cases.
   if (found == g_widget_to_internals_map.Pointer()->end())
     return NULL;
   return found->second;
 }
 
 }  // namespace content