Unset GL Api when releasing a context.

ui/gl/gl_bindings.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_BINDINGS_H_
 #define UI_GL_GL_BINDINGS_H_
 
 // Includes the platform independent and platform dependent GL headers.
 // Only include this in cc files. It pulls in system headers, including
 // the X11 headers on linux, which define all kinds of macros that are
 // liable to cause conflicts.
 
 #include <GL/gl.h>
 #include <GL/glext.h>
 #include <EGL/egl.h>
 #include <EGL/eglext.h>
 
+#include "base/lazy_instance.h"
 #include "base/logging.h"
+#include "base/threading/thread_local.h"
 #include "build/build_config.h"
 #include "ui/gl/gl_export.h"
 
 // The standard OpenGL native extension headers are also included.
 #if defined(OS_WIN)
 #include <GL/wglext.h>
 #elif defined(OS_MACOSX)
 #include <OpenGL/OpenGL.h>
 #elif defined(USE_X11)
 #include <GL/glx.h>
@@ skipping 249 matching lines @@
   void InitializeDebugBindings();
   void ClearBindings();
   void UpdateDebugExtensionBindings();
 
   ProcsGLX fn;
   ProcsGLX debug_fn;
   ExtensionsGLX ext;
 };
 #endif
 
-GL_EXPORT extern GLApi* g_current_gl_context;
+#define g_current_gl_context g_current_gl_context_tls.Pointer()->Get()

[no sievers, 2013/06/12 23:34:59]

I did this hack for the autogenerated code.

+GL_EXPORT extern base::LazyInstance<base::ThreadLocalPointer<GLApi> >
+    g_current_gl_context_tls;
 GL_EXPORT extern OSMESAApi* g_current_osmesa_context;
 GL_EXPORT extern DriverGL g_driver_gl;
 GL_EXPORT extern DriverOSMESA g_driver_osmesa;
 
 #if defined(OS_WIN)
 
 GL_EXPORT extern EGLApi* g_current_egl_context;
 GL_EXPORT extern WGLApi* g_current_wgl_context;
 GL_EXPORT extern DriverEGL g_driver_egl;
 GL_EXPORT extern DriverWGL g_driver_wgl;
@@ skipping 16 matching lines @@
 GL_EXPORT extern DriverEGL g_driver_egl;
 
 #endif
 
 // Find an entry point to the mock GL implementation.
 void* GL_BINDING_CALL GetMockGLProcAddress(const char* name);
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_BINDINGS_H_