Mac: Fix bad framerate when capturing tab

content/browser/compositor/browser_compositor_view_private_mac.mm

 // 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.
 
 #include "content/browser/compositor/browser_compositor_view_private_mac.h"
 
 #include "base/debug/trace_event.h"
 #include "content/browser/compositor/gpu_process_transport_factory.h"
 #include "content/browser/renderer_host/compositing_iosurface_context_mac.h"
 #include "content/browser/renderer_host/compositing_iosurface_mac.h"
@@ skipping 178 matching lines @@
                      withScaleFactor:scale_factor];
 
   // If there was an accelerated layer, remove it.
   {
     [accelerated_layer_ resetClient];
     [accelerated_layer_ removeFromSuperlayer];
     accelerated_layer_.reset();
   }
 }
 
+bool BrowserCompositorViewMacInternal::AcceleratedLayerShouldAckImmediately()
+    const {
+  // If there is no client then the accelerated layer is not in the hierarchy
+  // and will never draw.
+  if (!client_)
+    return true;
+  return client_->BrowserCompositorViewShouldAckImmediately();
+}
+
 void BrowserCompositorViewMacInternal::AcceleratedLayerDidDrawFrame(
     bool succeeded) {
   if (accelerated_layer_output_surface_id_) {
     content::ImageTransportFactory::GetInstance()->OnSurfaceDisplayed(
         accelerated_layer_output_surface_id_);
     accelerated_layer_output_surface_id_ = 0;
   }
 
   if (client_)
     client_->BrowserCompositorViewFrameSwapped(accelerated_latency_info_);
@@ skipping 44 matching lines @@
 - (void)gotSoftwareFrame:(cc::SoftwareFrameData*)frame_data
          withScaleFactor:(float)scale_factor
               withCanvas:(SkCanvas*)canvas {
   if (!client_)
     return;
   client_->GotSoftwareFrame(frame_data, scale_factor, canvas);
 }
 
 @end  // BrowserCompositorViewCocoa