Implementation of device metrics emulation in render view.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 020ff1bee86a62830910b859fcf25a86a1479316..c70392a48912486fcc2b19e2e3d08ae8f08b2e5e 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -800,6 +800,8 @@ bool RenderWidgetHostViewAura::ShouldCreateResizeLock() {
     return false;
 
   gfx::Size desired_size = window_->bounds().size();
+  if (!expected_rendered_size_.IsEmpty())
+    desired_size = expected_rendered_size_;
   if (desired_size == current_frame_size_)
     return false;
 
@@ -817,6 +819,8 @@ bool RenderWidgetHostViewAura::ShouldCreateResizeLock() {
 scoped_ptr<ResizeLock> RenderWidgetHostViewAura::CreateResizeLock(
     bool defer_compositor_lock) {
   gfx::Size desired_size = window_->bounds().size();
+  if (!expected_rendered_size_.IsEmpty())
+    desired_size = expected_rendered_size_;
   return scoped_ptr<ResizeLock>(new CompositorResizeLock(
       window_->GetRootWindow(),
       desired_size,
@@ -2082,6 +2086,10 @@ void RenderWidgetHostViewAura::GestureEventAck(int gesture_event_type,
     touch_editing_client_->GestureEventAck(gesture_event_type);
 }
 
+void RenderWidgetHostViewAura::SetExpectedRenderedSize(const gfx::Size& size) {
+  expected_rendered_size_ = size;
+}
+
 void RenderWidgetHostViewAura::ProcessAckedTouchEvent(
     const TouchEventWithLatencyInfo& touch, InputEventAckState ack_result) {
   ScopedVector<ui::TouchEvent> events;