Put the Pepper stuff in the content namespace.

content/renderer/pepper/pepper_platform_audio_input_impl.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_PLATFORM_AUDIO_INPUT_IMPL_H_
 #define CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_AUDIO_INPUT_IMPL_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "content/renderer/media/audio_input_message_filter.h"
 #include "media/audio/audio_parameters.h"
 #include "webkit/plugins/ppapi/plugin_delegate.h"
 
 class AudioParameters;
+
+namespace content {
+
 class PepperPluginDelegateImpl;
 
 // PepperPlatformAudioInputImpl is operated on two threads: the main thread (the
 // thread on which objects are created) and the I/O thread. All public methods,
 // except the destructor, must be called on the main thread. The notifications
 // to the users of this class (via the PlatformAudioInputClient interface) are
 // also sent on the main thread. Internally, this class sends audio input IPC
 // messages and receives AudioInputMessageFilter::Delegate notifications on the
 // I/O thread.
 class PepperPlatformAudioInputImpl
@@ skipping 71 matching lines @@
   // Whether ShutDownOnIOThread() has been called. THIS MUST ONLY BE ACCESSED ON
   // THE I/O THREAD.
   bool shutdown_called_;
 
   // Initialized on the main thread and accessed on the I/O thread afterwards.
   AudioParameters params_;
 
   DISALLOW_COPY_AND_ASSIGN(PepperPlatformAudioInputImpl);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_PLATFORM_AUDIO_INPUT_IMPL_H_