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

content/browser/renderer_host/compositing_iosurface_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/compositing_iosurface_mac.h"
 
+#include <OpenGL/CGLRenderers.h>
 #include <OpenGL/OpenGL.h>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/mac/mac_util.h"
 #include "base/message_loop.h"
 #include "base/threading/platform_thread.h"
 #include "content/common/content_constants_internal.h"
 #include "content/port/browser/render_widget_host_view_frame_subscriber.h"
@@ skipping 325 matching lines @@
 }
 
 void CompositingIOSurfaceMac::SetIOSurface(uint64 io_surface_handle,
                                            const gfx::Size& size) {
   pixel_io_surface_size_ = size;
   CGLSetCurrentContext(cglContext_);
   MapIOSurfaceToTexture(io_surface_handle);
   CGLSetCurrentContext(0);
 }
 
+int CompositingIOSurfaceMac::GetRendererID() {
+  GLint current_renderer_id = -1;
+  if (CGLGetParameter(cglContext_,
+                      kCGLCPCurrentRendererID,
+                      &current_renderer_id) == kCGLNoError)
+    return current_renderer_id & kCGLRendererIDMatchingMask;
+  return -1;
+}
+
 void CompositingIOSurfaceMac::DrawIOSurface(
     NSView* view, float scale_factor,
     RenderWidgetHostViewFrameSubscriber* frame_subscriber) {
   CGLSetCurrentContext(cglContext_);
 
   bool has_io_surface = MapIOSurfaceToTexture(io_surface_handle_);
 
   TRACE_EVENT1("browser", "CompositingIOSurfaceMac::DrawIOSurface",
                "has_io_surface", has_io_surface);
 
@@ skipping 661 matching lines @@
 }
 
 gfx::Rect CompositingIOSurfaceMac::IntersectWithIOSurface(
     const gfx::Rect& rect, float scale_factor) const {
   return gfx::IntersectRects(rect,
       gfx::ToEnclosingRect(gfx::ScaleRect(gfx::Rect(io_surface_size_),
                                           scale_factor)));
 }
 
 }  // namespace content