Move content's a plugin, ppapi_plugin, utility, and worker subdirectories to the content namespace.

content/ppapi_plugin/ppapi_webkitplatformsupport_impl.h

Index: content/ppapi_plugin/ppapi_webkitplatformsupport_impl.h
===================================================================
--- content/ppapi_plugin/ppapi_webkitplatformsupport_impl.h	(revision 163080)
+++ content/ppapi_plugin/ppapi_webkitplatformsupport_impl.h	(working copy)
@@ -9,8 +9,9 @@
 #include "base/memory/scoped_ptr.h"
 #include "content/common/webkitplatformsupport_impl.h"
 
-class PpapiWebKitPlatformSupportImpl :
-    public content::WebKitPlatformSupportImpl {
+namespace content {
+
+class PpapiWebKitPlatformSupportImpl : public WebKitPlatformSupportImpl {
  public:
   PpapiWebKitPlatformSupportImpl();
   virtual ~PpapiWebKitPlatformSupportImpl();
@@ -55,4 +56,6 @@
   DISALLOW_COPY_AND_ASSIGN(PpapiWebKitPlatformSupportImpl);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_PPAPI_PLUGIN_PPAPI_WEBKITPLATFORMSUPPORT_IMPL_H_