Move a bunch of code in content\renderer to the content namespace.

content/renderer/media/render_audiosourceprovider.cc

Index: content/renderer/media/render_audiosourceprovider.cc
===================================================================
--- content/renderer/media/render_audiosourceprovider.cc	(revision 163045)
+++ content/renderer/media/render_audiosourceprovider.cc	(working copy)
@@ -16,11 +16,11 @@
 #include "media/base/audio_renderer_mixer_input.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebAudioSourceProviderClient.h"
 
-using content::AudioDeviceFactory;
-using content::AudioRendererMixerManager;
 using std::vector;
 using WebKit::WebVector;
 
+namespace content {
+
 RenderAudioSourceProvider::RenderAudioSourceProvider()
     : is_initialized_(false),
       channels_(0),
@@ -149,3 +149,5 @@
 }
 
 RenderAudioSourceProvider::~RenderAudioSourceProvider() {}
+
+}  // namespace content