Add initial code to do filename munging in the FileSystem....

webkit/fileapi/file_system_path_manager.h

Index: webkit/fileapi/file_system_path_manager.h
===================================================================
--- webkit/fileapi/file_system_path_manager.h	(revision 74905)
+++ webkit/fileapi/file_system_path_manager.h	(working copy)
@@ -51,14 +51,17 @@
                              GetRootPathCallback* callback);
 
   // Cracks the given |path|, retrieves the information embedded in the path
-  // and populates |origin_url| and |type|.  Also it populates |virtual_path|
-  // that is a sandboxed path in the file system, i.e. the relative path to
-  // the file system's root path for the given origin and type.
-  // It returns false if the path does not conform to the expected
-  // filesystem path format.
+  // and populates |origin_url| and |type|.  Also it populates |root| and
+  // |virtual_path|, where |virtual_path| is a sandboxed path in the file
+  // system, i.e. the relative path to the filesystem root for the given domain
+  // and type.  Concatenate |root| and |virtual_path| to get a canonical form of
+  // |path|.
+  // It returns false if the path does not conform to the expected filesystem
+  // path format.
   bool CrackFileSystemPath(const FilePath& path,
                            GURL* origin_url,
                            FileSystemType* type,
+                           FilePath* root,
                            FilePath* virtual_path) const;
 
   // Checks if a given |name| contains any restricted names/chars in it.