Mac Overlays: Add GPU back-pressure

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 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/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ skipping 497 matching lines @@
       // immediately.
       return true;
     }
   }
 
   // If the window occlusion API is not present then ack frames when we draw
   // them.
   return false;
 }
 
+uint32_t RenderWidgetHostViewMac::AcceleratedWidgetGetDisplayIDForVSync()
+    const {
+  if (display_link_)
+    return display_link_->display_id();
+  return 0;
+}
+
 void RenderWidgetHostViewMac::AcceleratedWidgetSwapCompleted(
     const std::vector<ui::LatencyInfo>& all_latency_info) {
   if (!render_widget_host_)
     return;
   base::TimeTicks swap_time = base::TimeTicks::Now();
   for (auto latency_info : all_latency_info) {
     latency_info.AddLatencyNumberWithTimestamp(
         ui::INPUT_EVENT_GPU_SWAP_BUFFER_COMPONENT, 0, 0, swap_time, 1);
     latency_info.AddLatencyNumberWithTimestamp(
         ui::INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT, 0, 0,
@@ skipping 2774 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end