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

ui/gl/gl_wgl_api_implementation.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_WGL_API_IMPLEMENTATION_H_
 #define UI_GL_GL_WGL_API_IMPLEMENTATION_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 37 matching lines @@
 
   const char* wglGetExtensionsStringARBFn(HDC hDC) override;
   const char* wglGetExtensionsStringEXTFn() override;
  private:
 
   std::vector<std::string> disabled_exts_;
   std::string filtered_arb_exts_;
   std::string filtered_ext_exts_;
 };
 
+// Logs debug information for every WGL call.
+class GL_EXPORT DebugWGLApi : public WGLApi {
+ public:
+  DebugWGLApi(WGLApi* wgl_api);
+  ~DebugWGLApi() override;
+
+  // Include the auto-generated part of this class. We split this because
+  // it means we can easily edit the non-auto generated parts right here in
+  // this file instead of having to edit some template or the code generator.
+  #include "gl_bindings_api_autogen_wgl.h"
+
+ private:
+  WGLApi* wgl_api_;
+};
+
 // Inserts a TRACE for every WGL call.
 class GL_EXPORT TraceWGLApi : public WGLApi {
  public:
   TraceWGLApi(WGLApi* wgl_api) : wgl_api_(wgl_api) { }
   ~TraceWGLApi() override;
 
   // Include the auto-generated part of this class. We split this because
   // it means we can easily edit the non-auto generated parts right here in
   // this file instead of having to edit some template or the code generator.
   #include "gl_bindings_api_autogen_wgl.h"
 
  private:
   WGLApi* wgl_api_;
 };
 
 }  // namespace gl
 
 #endif  // UI_GL_GL_WGL_API_IMPLEMENTATION_H_