cc: Use max_bytes_per_copy_operation setting to determine one-copy flush interval.

content/renderer/gpu/render_widget_compositor.cc

Index: content/renderer/gpu/render_widget_compositor.cc
diff --git a/content/renderer/gpu/render_widget_compositor.cc b/content/renderer/gpu/render_widget_compositor.cc
index 487613598b5959945b99c3b821b15f107910a7f7..159fcc6dd4cc935f90a8de87ae65233d2f9e699e 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -178,6 +178,11 @@ gfx::Size CalculateDefaultTileSize(RenderWidget* widget) {
   return gfx::Size(default_tile_size, default_tile_size);
 }
 
+size_t GetMaxBytesPerCopyOperation() {

[vmpstr, 2015/06/01 18:35:52]

Leave a comment here explaining the rationale for 4MB as the number.

[vmpstr, 2015/06/02 23:23:27]

Can you also make this int?

[reveman, 2015/06/04 01:19:51]

Done.
Done.

+  const size_t kMegabyte = 1024 * 1024;
+  return kMegabyte * 4;
+}
+
 // Check cc::TopControlsState, and blink::WebTopControlsState
 // are kept in sync.
 static_assert(int(blink::WebTopControlsBoth) == int(cc::BOTH),
@@ -458,6 +463,8 @@ void RenderWidgetCompositor::Initialize() {
     settings.use_external_begin_frame_source = false;
   }
 
+  settings.max_bytes_per_copy_operation = GetMaxBytesPerCopyOperation();
+
   scoped_refptr<base::SingleThreadTaskRunner> compositor_thread_task_runner =
       compositor_deps_->GetCompositorImplThreadTaskRunner();
   scoped_refptr<base::SingleThreadTaskRunner>