Mac: Fix bad framerate when capturing tab

content/browser/compositor/browser_compositor_view_mac.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_VIEW_MAC_H_
 #define CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 #include <IOSurface/IOSurfaceAPI.h>
 #include <vector>
@@ skipping 23 matching lines @@
 
 namespace content {
 
 class BrowserCompositorViewMacInternal;
 
 // The interface through which BrowserCompositorViewMac calls back into
 // RenderWidgetHostViewMac (or any other structure that wishes to draw a
 // NSView backed by a ui::Compositor).
 class BrowserCompositorViewMacClient {
  public:
+  // Drawing is usually throttled by the rate at which CoreAnimation draws
+  // frames to the screen. This can be used to disable throttling.
+  virtual bool BrowserCompositorViewShouldAckImmediately() const = 0;
+
   // Called when a frame is drawn, and used to pass latency info back to the
   // renderer (if any).
   virtual void BrowserCompositorViewFrameSwapped(
       const std::vector<ui::LatencyInfo>& latency_info) = 0;
 
   // Used to install the ui::Compositor-backed NSView as a child of its parent
   // view.
   virtual NSView* BrowserCompositorSuperview() = 0;
 
   // Used to install the root ui::Layer into the ui::Compositor.
@@ skipping 29 matching lines @@
 // next BrowserCompositorViewMac to be created will be be created quickly.
 class BrowserCompositorViewPlaceholderMac {
  public:
   BrowserCompositorViewPlaceholderMac();
   ~BrowserCompositorViewPlaceholderMac();
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_COMPOSITOR_BROWSER_COMPOSITOR_VIEW_MAC_H_