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..cf918b54464fc2264c2b1232c5b9821c27ddd583 100644
--- a/ui/gl/gl_surface.h
+++ b/ui/gl/gl_surface.h
@@ -16,6 +16,7 @@
 namespace gfx {
 
 class GLContext;
+class VirtualGLApi;
 class VSyncProvider;
 
 // Encapsulates a surface that can be rendered to with GL, hiding platform
@@ -107,19 +108,27 @@ 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();
 
  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);
 
+  // Returns the last GLSurface made current with a real (non-virtual) context.
+  static GLSurface* GetRealCurrent();
+
  private:
   friend class base::RefCounted<GLSurface>;
   friend class GLContext;
 
+  // For GetRealCurrent.
+  friend class VirtualGLApi;
+
   DISALLOW_COPY_AND_ASSIGN(GLSurface);
 };