Put the Pepper stuff in the content namespace.

content/renderer/pepper/pepper_parent_context_provider.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 CONTENT_RENDERER_PEPPER_PEPPER_PARENT_CONTEXT_PROVIDER_H_
 #define CONTENT_RENDERER_PEPPER_PEPPER_PARENT_CONTEXT_PROVIDER_H_
 #pragma once
 
 #include "base/basictypes.h"
 
 class ContentGLContext;
 
+namespace content {
+
 // Defines the mechanism by which a Pepper 3D context fetches its
 // parent context for display to the screen.
 class PepperParentContextProvider {
  public:
   virtual ~PepperParentContextProvider();
   virtual ContentGLContext* GetParentContextForPlatformContext3D() = 0;
 
  protected:
   PepperParentContextProvider();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PepperParentContextProvider);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_PARENT_CONTEXT_PROVIDER_H_