Refactor GL bindings so there is no global GLApi or DriverGL.

ui/gl/gl_glx_api_implementation.cc

 // 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.
 
 #include "ui/gl/gl_glx_api_implementation.h"
 
 #include "base/command_line.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "ui/gl/gl_implementation.h"
 
 namespace gl {
 
 RealGLXApi* g_real_glx;
+DebugGLXApi* g_debug_glx;
 
 void InitializeStaticGLBindingsGLX() {
   g_driver_glx.InitializeStaticBindings();
   if (!g_real_glx) {
     g_real_glx = new RealGLXApi();
   }
   g_real_glx->Initialize(&g_driver_glx);
   g_current_glx_context = g_real_glx;
   g_driver_glx.InitializeExtensionBindings();
 }
 
 void InitializeDebugGLBindingsGLX() {
-  g_driver_glx.InitializeDebugBindings();
+  if (!g_debug_glx) {
+    g_debug_glx = new DebugGLXApi(g_real_glx);
+  }
+  g_current_glx_context = g_debug_glx;
 }
 
 void ClearBindingsGLX() {
+  if (g_debug_glx) {
+    delete g_debug_glx;
+    g_debug_glx = NULL;
+  }
   if (g_real_glx) {
     delete g_real_glx;
     g_real_glx = NULL;
   }
   g_current_glx_context = NULL;
   g_driver_glx.ClearBindings();
 }
 
 GLXApi::GLXApi() {
 }
@@ skipping 48 matching lines @@
     return NULL;
 
   const char* str = GLXApiBase::glXQueryExtensionsStringFn(dpy, screen);
   if (!str)
     return NULL;
 
   filtered_exts_ = FilterGLExtensionList(str, disabled_exts_);
   return filtered_exts_.c_str();
 }
 
+DebugGLXApi::DebugGLXApi(GLXApi* glx_api) : glx_api_(glx_api) {}
+DebugGLXApi::~DebugGLXApi() {}
+
 TraceGLXApi::~TraceGLXApi() {
 }
 
 bool GetGLWindowSystemBindingInfoGLX(GLWindowSystemBindingInfo* info) {
   Display* display = glXGetCurrentDisplay();
   const int kDefaultScreen = 0;
   const char* vendor =
       glXQueryServerString(display, kDefaultScreen, GLX_VENDOR);
   const char* version =
       glXQueryServerString(display, kDefaultScreen, GLX_VERSION);
   const char* extensions =
       glXQueryServerString(display, kDefaultScreen, GLX_EXTENSIONS);
   *info = GLWindowSystemBindingInfo();
   if (vendor)
     info->vendor = vendor;
   if (version)
     info->version = version;
   if (extensions)
     info->extensions = extensions;
   info->direct_rendering = !!glXIsDirect(display, glXGetCurrentContext());
   return true;
 }
 
 }  // namespace gl