Revert of Use a single CGLContextObj to draw and update the IOSurface

content/browser/compositor/io_surface_layer_mac.h

Index: content/browser/compositor/io_surface_layer_mac.h
diff --git a/content/browser/compositor/io_surface_layer_mac.h b/content/browser/compositor/io_surface_layer_mac.h
index a52a75cc95f88a0ff846e13efa2a9cb29a4dc010..5a218e8f66529e0b94e40ba596d5ea73d3defcfd 100644
--- a/content/browser/compositor/io_surface_layer_mac.h
+++ b/content/browser/compositor/io_surface_layer_mac.h
@@ -16,6 +16,7 @@
 
 namespace content {
 class IOSurfaceTexture;
+class IOSurfaceContext;
 
 // The interface through which the IOSurfaceLayer calls back into
 // the structrue that created it (RenderWidgetHostViewMac or
@@ -116,6 +117,8 @@
 @interface IOSurfaceLayer : CAOpenGLLayer {
  @private
   scoped_refptr<content::IOSurfaceTexture> iosurface_;
+  scoped_refptr<content::IOSurfaceContext> context_;
+
   scoped_ptr<content::IOSurfaceLayerHelper> helper_;
 }