Follow-up fixes to changing namespace gfx to gl.

ui/gl/gl_context_stub_with_extensions.h

 // Copyright 2014 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_CONTEXT_STUB_WITH_EXTENSIONS_H_
 #define UI_GL_GL_CONTEXT_STUB_WITH_EXTENSIONS_H_
 
 #include "base/macros.h"
 #include "ui/gl/gl_context_stub.h"
 #include "ui/gl/gl_export.h"
 
 namespace gl {
 
 // Lightweight GLContext stub implementation that returns a constructed
 // extensions string.  We use this to create a context that we can use to
 // initialize GL extensions with, without actually creating a platform context.
-class GL_EXPORT GLContextStubWithExtensions : public gl::GLContextStub {
+class GL_EXPORT GLContextStubWithExtensions : public GLContextStub {
  public:
   GLContextStubWithExtensions() {}
   std::string GetExtensions() override;
 
   void AddExtensionsString(const char* extensions);
   void SetGLVersionString(const char* version_str);
   bool WasAllocatedUsingRobustnessExtension() override;
 
  protected:
   std::string GetGLVersion() override;
 
   ~GLContextStubWithExtensions() override {}
 
  private:
   std::string extensions_;
   std::string version_str_;
 
   DISALLOW_COPY_AND_ASSIGN(GLContextStubWithExtensions);
 };
 
 }  // namespace gl
 
 #endif  // UI_GL_GL_CONTEXT_STUB_WITH_EXTENSIONS_H_