Switch all contexts in a share group to be on the same screen as the window they present to.

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"
 
 #include <QuartzCore/QuartzCore.h>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 1142 matching lines @@
   }
   return true;
 }
 
 void RenderWidgetHostViewMac::AckPendingSwapBuffers() {
   TRACE_EVENT0("browser", "RenderWidgetHostViewMac::AckPendingSwapBuffers");
   while (!pending_swap_buffers_acks_.empty()) {
     if (pending_swap_buffers_acks_.front().first != 0) {
       AcceleratedSurfaceMsg_BufferPresented_Params ack_params;
       ack_params.sync_point = 0;
+      if (compositing_iosurface_.get())
+        ack_params.renderer_id = compositing_iosurface_->GetRendererID();
       RenderWidgetHostImpl::AcknowledgeBufferPresent(
           pending_swap_buffers_acks_.front().first,
           pending_swap_buffers_acks_.front().second,
           ack_params);
       if (render_widget_host_) {
         render_widget_host_->AcknowledgeSwapBuffersToRenderer();
 
         // Send VSync parameters to compositor thread.
         if (compositing_iosurface_.get()) {
           base::TimeTicks timebase;
@@ skipping 2363 matching lines @@
   if (!string) return NO;
 
   // If the user is currently using an IME, confirm the IME input,
   // and then insert the text from the service, the same as TextEdit and Safari.
   [self confirmComposition];
   [self insertText:string];
   return YES;
 }
 
 @end