Mac: Only allow NSOpenGLContext displaying on the main display

content/common/gpu/image_transport_surface_fbo_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/common/gpu/image_transport_surface_fbo_mac.h"
 
 #include "base/trace_event/trace_event.h"
 #include "content/common/gpu/gpu_messages.h"
 #include "content/common/gpu/image_transport_surface_calayer_mac.h"
 #include "content/common/gpu/image_transport_surface_iosurface_mac.h"
@@ skipping 162 matching lines @@
   TRACE_EVENT0("gpu", "ImageTransportSurfaceFBO::SwapBuffers");
   pending_swap_pixel_damage_rect_ = gfx::Rect(pixel_size_);
   return SwapBuffersInternal() ? gfx::SwapResult::SWAP_ACK
                                : gfx::SwapResult::SWAP_FAILED;
 }
 
 bool ImageTransportSurfaceFBO::SwapBuffersInternal() {
   DCHECK(backbuffer_suggested_allocation_);
   if (!frontbuffer_suggested_allocation_)
     return true;
-  glFlush();
+
+  {
+    TRACE_EVENT0("gpu", "ImageTransportSurfaceFBO::glFlush");
+    glFlush();
+  }
 
   // It is the responsibility of the storage provider to send the swap IPC.
   is_swap_buffers_send_pending_ = true;
   storage_provider_->SwapBuffers();
 
   // The call to swapBuffers could potentially result in an immediate draw.
   // Ensure that any changes made to the context's state are restored.
   context_->RestoreStateIfDirtiedExternally();
   return true;
 }
@@ skipping 221 matching lines @@
   }
 
   has_complete_framebuffer_ = true;
   storage_provider_->FrameSizeChanged(pixel_size_, scale_factor_);
 
   glBindTexture(texture_target, previous_texture_id);
   // The FBO remains bound for this GL context.
 }
 
 }  // namespace content