Re-land: cc: Use worker context for one-copy tile initialization.

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 f69dc63100a75ae10b8464e8e158d88c818c182a..705937aef1cb97930a4a5c9c16d1a460a4036502 100644
--- a/content/renderer/gpu/render_widget_compositor.cc
+++ b/content/renderer/gpu/render_widget_compositor.cc
@@ -470,6 +470,11 @@ void RenderWidgetCompositor::Initialize() {
     settings.use_external_begin_frame_source = false;
   }
 
+  settings.max_staging_buffers = 32;
+  // Use 1/4th of staging buffers on low-end devices.
+  if (base::SysInfo::IsLowEndDevice())
+    settings.max_staging_buffers /= 4;
+
   scoped_refptr<base::SingleThreadTaskRunner> compositor_thread_task_runner =
       compositor_deps_->GetCompositorImplThreadTaskRunner();
   scoped_refptr<base::SingleThreadTaskRunner>