Mac: Fix bad framerate when capturing tab

content/browser/renderer_host/compositing_iosurface_layer_mac.mm

 // Copyright 2013 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/compositing_iosurface_layer_mac.h"
 
 #include <CoreFoundation/CoreFoundation.h>
 #include <OpenGL/gl.h>
 
 #include "base/mac/mac_util.h"
@@ skipping 25 matching lines @@
               this,
               &CompositingIOSurfaceLayerHelper::TimerFired) {}
 
 CompositingIOSurfaceLayerHelper::~CompositingIOSurfaceLayerHelper() {
   // Any acks that were waiting on this layer to draw will not occur, so ack
   // them now to prevent blocking the renderer.
   AckPendingFrame(true);
 }
 
 void CompositingIOSurfaceLayerHelper::GotNewFrame() {
+  // A trace value of 2 indicates that there is a pending swap ack. See
+  // canDrawInCGLContext for other value meanings.
+  TRACE_COUNTER_ID1("browser", "PendingSwapAck", this, 2);
+
   has_pending_frame_ = true;
   needs_display_ = true;
   timer_.Reset();
 
-  if ([layer_ context] && [layer_ context]->is_vsync_disabled()) {
-    // If vsync is disabled, draw immediately and don't bother trying to use
-    // the isAsynchronous property to ensure smooth animation.
+  // If reqested, draw immediately and don't bother trying to use the
+  // isAsynchronous property to ensure smooth animation.
+  if (client_->AcceleratedLayerShouldAckImmediately()) {
     ImmediatelyForceDisplayAndAck();
   } else {
-    needs_display_ = YES;
     if (![layer_ isAsynchronous])
       [layer_ setAsynchronous:YES];
   }
-
-  // A trace value of 2 indicates that there is a pending swap ack. See
-  // canDrawInCGLContext for other value meanings.
-  TRACE_COUNTER_ID1("browser", "PendingSwapAck", this, 2);
 }
 
 void CompositingIOSurfaceLayerHelper::SetNeedsDisplay() {
   needs_display_ = true;
 }
 
 bool CompositingIOSurfaceLayerHelper::CanDraw() {
   // If we return NO 30 times in a row, switch to being synchronous to avoid
   // burning CPU cycles on this callback.
   if (needs_display_) {
@@ skipping 158 matching lines @@
   if (helper_)
     helper_->DidDraw(draw_succeeded);
 
   [super drawInCGLContext:glContext
               pixelFormat:pixelFormat
              forLayerTime:timeInterval
               displayTime:timeStamp];
 }
 
 @end