Android: Use virtualized context only for those with compatible config

ui/gl/gl_share_group.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_SHARE_GROUP_H_
 #define UI_GL_GL_SHARE_GROUP_H_
 
+#include <map>
 #include <set>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "build/build_config.h"
 #include "ui/gl/gl_export.h"
+#include "ui/gl/gl_surface.h"
+#include "ui/gl/gpu_preference.h"
 
 namespace gfx {
 
 class GLContext;
 
 // A group of GL contexts that share an ID namespace.
 class GL_EXPORT GLShareGroup : public base::RefCounted<GLShareGroup> {
  public:
   GLShareGroup();
 
   // These two should only be called from the constructor and destructor of
   // GLContext.
   void AddContext(GLContext* context);
   void RemoveContext(GLContext* context);
 
   // Returns a handle to any initialized context in the share group or NULL if
   // there are no initialized contexts in the share group.
   void* GetHandle();
 
   // Returns a pointer to any initialized context in the share group
   // or NULL if there are no initialized contexts in the share group.
   GLContext* GetContext();
 
-  // Sets and returns the unique shared GL context. Used for context
-  // virtualization.
-  void SetSharedContext(GLContext* context);
+  // Updates the shared context pool and sets the active shared GL context
+  // used for virtualization to match the configuration.
+  void UpdateActiveSharedContext(GLSurface* surface, GpuPreference preference);
   GLContext* GetSharedContext();
 
 #if defined(OS_MACOSX)
   // Sets and returns the ID of the renderer that all contexts in this share
   // group should be on.
   void SetRendererID(int renderer_id);
   int GetRendererID();
 #endif
 
  private:
   friend class base::RefCounted<GLShareGroup>;
 
   ~GLShareGroup();
 
   // References to GLContext are by raw pointer to avoid a reference count
   // cycle.
   typedef std::set<GLContext*> ContextSet;
   ContextSet contexts_;
 
-  GLContext* shared_context_;
+  // USe refptr for GL Contexts to keep the shared contexts temporarily not
+  // referenced by any virtual GL context. Will be destroyed together with
+  // the share group.
+  scoped_ptr<std::map<GLSurface::Format,
+                      scoped_refptr<GLContext>>> shared_contexts_;
+  GLContext* active_context_;
+  GLSurface::Format format_;
 
 #if defined(OS_MACOSX)
   int renderer_id_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(GLShareGroup);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SHARE_GROUP_H_