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

ui/gl/gl_context.h

 // 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.
 
 #ifndef UI_GL_GL_CONTEXT_H_
 #define UI_GL_GL_CONTEXT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 70 matching lines @@
   // Create a GL context that is compatible with the given surface.
   // |share_group|, if non-NULL, is a group of contexts which the
   // internally created OpenGL context shares textures and other resources.
   static scoped_refptr<GLContext> CreateGLContext(
       GLShareGroup* share_group,
       GLSurface* compatible_surface,
       GpuPreference gpu_preference);
 
   static bool LosesAllContextsOnContextLost();
 
+  // Returns the last GLContext made current, virtual or real.
   static GLContext* GetCurrent();
 
   virtual bool WasAllocatedUsingRobustnessExtension();
 
   // Use this context for virtualization.
   void SetupForVirtualization();
 
   // Make this context current when used for context virtualization.
   bool MakeVirtuallyCurrent(GLContext* virtual_context, GLSurface* surface);
 
   // Notify this context that |virtual_context|, that was using us, is
   // being released or destroyed.
   void OnReleaseVirtuallyCurrent(GLContext* virtual_context);
 
  protected:
   virtual ~GLContext();
 
   // Sets the GL api to the real hardware API (vs the VirtualAPI)
   static void SetRealGLApi();
-  static void SetCurrent(GLContext* context, GLSurface* surface);
+  virtual void SetCurrent(GLSurface* surface);
 
   // Initialize function pointers to extension functions in the GL
   // implementation. Should be called immediately after this context is made
   // current.
   bool InitializeExtensionBindings();
 
+  // Returns the last real (non-virtual) GLContext made current.
+  static GLContext* GetRealCurrent();

[no sievers, 2013/06/05 16:43:37]

Acutally, can we do this now instead:

GLContext::GetCurrent()->GetRealContext() with GetRealContext() being virtual.

GLContext* GLContextReal::GetRealContext() {
  return this;
}

GLContext* GLContextVirtual::GetRealContext() {
  return shared_context_;
}

[jonathan.backer, 2013/06/05 20:40:11]

This is fundamentally the same as IsVirtualContext() no? Specifically,
IsVirtualContext() is equivalent to (this == GetRealContext()).

+
  private:
   friend class base::RefCounted<GLContext>;
 
+  // For GetRealCurrent.
+  friend class VirtualGLApi;
+
   scoped_refptr<GLShareGroup> share_group_;
   scoped_ptr<VirtualGLApi> virtual_gl_api_;
   scoped_ptr<GLStateRestorer> state_restorer_;
 
   DISALLOW_COPY_AND_ASSIGN(GLContext);
 };
 
+class GL_EXPORT GLContextReal : public GLContext {
+ public:
+  explicit GLContextReal(GLShareGroup* share_group);
+
+ protected:
+  virtual ~GLContextReal();
+
+  virtual void SetCurrent(GLSurface* surface) OVERRIDE;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(GLContextReal);
+};
+
 }  // namespace gfx
 
 #endif  // UI_GL_GL_CONTEXT_H_