Move a bunch of code in content\common (as well as a few left in renderer) to the content namespace.

content/common/fileapi/webfilesystem_impl.h

Index: content/common/fileapi/webfilesystem_impl.h
===================================================================
--- content/common/fileapi/webfilesystem_impl.h	(revision 163290)
+++ content/common/fileapi/webfilesystem_impl.h	(working copy)
@@ -15,6 +15,8 @@
 class WebFileWriterClient;
 }
 
+namespace content {
+
 class WebFileSystemImpl : public WebKit::WebFileSystem {
  public:
   WebFileSystemImpl();
@@ -63,4 +65,6 @@
       WebKit::WebFileSystemCallbacks*) OVERRIDE;
 };
 
+}  // namespace content
+
 #endif  // CONTENT_COMMON_FILEAPI_WEBFILESYSTEM_IMPL_H_