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

ui/gl/gl_osmesa_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_OSMESA_API_IMPLEMENTATION_H_
 #define UI_GL_GL_OSMESA_API_IMPLEMENTATION_H_
 
 #include "base/compiler_specific.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_export.h"
@@ skipping 19 matching lines @@
   DriverOSMESA* driver_;
 };
 
 class GL_EXPORT RealOSMESAApi : public OSMESAApiBase {
  public:
   RealOSMESAApi();
   ~RealOSMESAApi() override;
   void Initialize(DriverOSMESA* driver);
 };
 
+// Logs debug information for every OSMESA call.
+class GL_EXPORT DebugOSMESAApi : public OSMESAApi {
+ public:
+  DebugOSMESAApi(OSMESAApi* osmesa_api);
+  ~DebugOSMESAApi() 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_osmesa.h"
+
+ private:
+  OSMESAApi* osmesa_api_;
+};
+
 // Inserts a TRACE for every OSMESA call.
 class GL_EXPORT TraceOSMESAApi : public OSMESAApi {
  public:
   TraceOSMESAApi(OSMESAApi* osmesa_api) : osmesa_api_(osmesa_api) { }
   ~TraceOSMESAApi() 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_osmesa.h"
 
  private:
   OSMESAApi* osmesa_api_;
 };
 
 }  // namespace gl
 
 #endif  // UI_GL_GL_OSMESA_API_IMPLEMENTATION_H_