GPU: Keep track of the last real context and real surface made current.

ui/gl/gl_surface.h

Index: ui/gl/gl_surface.h
diff --git a/ui/gl/gl_surface.h b/ui/gl/gl_surface.h
index a8825a58c5a4a1af229047342862c6f746b9fe7a..42eb33315318999c4981e018d5cfdd8cfdf1e879 100644
--- a/ui/gl/gl_surface.h
+++ b/ui/gl/gl_surface.h
@@ -107,12 +107,17 @@ class GL_EXPORT GLSurface : public base::RefCounted<GLSurface> {
       bool software,
       const gfx::Size& size);
 
+  // Returns the last GLSurface made current, virtual or real.
   static GLSurface* GetCurrent();
 
+  // Returns the last real GLSurface made current.
+  static GLSurface* GetRealCurrent();
+
  protected:
   virtual ~GLSurface();
   static bool InitializeOneOffInternal();
   static void SetCurrent(GLSurface* surface);
+  static void SetRealCurrent(GLSurface* surface);
 
   static bool ExtensionsContain(const char* extensions, const char* name);