Destroy GLX windows when they are backgrounded

ui/gl/gl_surface_glx.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_SURFACE_GLX_H_
 #define UI_GL_GL_SURFACE_GLX_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 51 matching lines @@
   virtual void* GetHandle() OVERRIDE;
   virtual std::string GetExtensions() OVERRIDE;
   virtual void* GetConfig() OVERRIDE;
   virtual bool PostSubBuffer(int x, int y, int width, int height) OVERRIDE;
   virtual VSyncProvider* GetVSyncProvider() OVERRIDE;
 
  protected:
   NativeViewGLSurfaceGLX();
   virtual ~NativeViewGLSurfaceGLX();
 
-  gfx::AcceleratedWidget window_;
+ private:
+  // The handle for the drawable to make current or swap.
+  gfx::AcceleratedWidget GetDrawableHandle() const;
 
- private:
+  // Window passed in at creation. Always valid.
+  gfx::AcceleratedWidget parent_window_;
+
+#if defined(TOOLKIT_GTK)
+  // Some NVIDIA drivers don't allow deleting GLX windows separately from their
+  // parent X windows. Work around this by creating a child X window to the
+  // window passed in to the constructor, creating the GLX window against the
+  // child window, and then destroying the child window to destroy the GLX
+  // window.
+  // http://crbug.com/145600
+  virtual bool SetBackbufferAllocation(bool allocated) OVERRIDE;
+  bool CreateChildWindow();
+  void DestroyChildWindow();
+
+  // Child window which is used with GLX, and is discarded when it is
+  // backgrounded.
+  gfx::AcceleratedWidget child_window_;
+
+  // Dummy 1x1 window which is supplied to glXMakeCurrent when making
+  // the context current while its output surface is destroyed.
+  gfx::AcceleratedWidget dummy_window_;
+#endif
+
   void* config_;
   gfx::Size size_;
 
   scoped_ptr<VSyncProvider> vsync_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeViewGLSurfaceGLX);
 };
 
 // A surface used to render to an offscreen pbuffer.
 class GL_EXPORT PbufferGLSurfaceGLX : public GLSurfaceGLX {
@@ skipping 16 matching lines @@
   gfx::Size size_;
   void* config_;
   XID pbuffer_;
 
   DISALLOW_COPY_AND_ASSIGN(PbufferGLSurfaceGLX);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SURFACE_GLX_H_