Aura: add a bench utility

ui/compositor/layer.cc

Index: ui/compositor/layer.cc
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index d5f0c445e8a45fd22ff7ee80218a45fc774432e9..6e84107d4f0b561f85ab55dd4cde8dd73b7a3096 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -49,6 +49,7 @@ Layer::Layer()
       compositor_(NULL),
       parent_(NULL),
       visible_(true),
+      force_render_surface_(false),
       fills_bounds_opaquely_(true),
       layer_updated_externally_(false),
       opacity_(1.0f),
@@ -63,6 +64,7 @@ Layer::Layer(LayerType type)
       compositor_(NULL),
       parent_(NULL),
       visible_(true),
+      force_render_surface_(false),
       fills_bounds_opaquely_(true),
       layer_updated_externally_(false),
       opacity_(1.0f),
@@ -296,6 +298,7 @@ void Layer::SetExternalTexture(Texture* texture) {
     web_layer_.setOpaque(fills_bounds_opaquely_);
     web_layer_.setOpacity(visible_ ? opacity_ : 0.f);
     web_layer_.setDebugBorderWidth(show_debug_borders_ ? 2 : 0);
+    web_layer_.setForceRenderSurface(force_render_surface_);
     RecomputeTransform();
     RecomputeDebugBorderColor();
   }
@@ -399,6 +402,14 @@ void Layer::paintContents(WebKit::WebCanvas* web_canvas,
     canvas.Restore();
 }
 
+void Layer::SetForceRenderSurface(bool force) {
+  if (force_render_surface_ == force)
+    return;
+
+  force_render_surface_ = force;
+  web_layer_.setForceRenderSurface(force_render_surface_);
+}
+
 float Layer::GetCombinedOpacity() const {
   float opacity = opacity_;
   Layer* current = this->parent_;