Fix filesystem API file_handlers to work for drive on ChromeOS.

webkit/fileapi/external_mount_points.h

Index: webkit/fileapi/external_mount_points.h
diff --git a/webkit/fileapi/external_mount_points.h b/webkit/fileapi/external_mount_points.h
index a2660c24536d118b643e29f8baadc9fadeb786fb..7e732453e92f85119844e4c06f8dc169f0c871d0 100644
--- a/webkit/fileapi/external_mount_points.h
+++ b/webkit/fileapi/external_mount_points.h
@@ -81,12 +81,14 @@ class WEBKIT_STORAGE_EXPORT ExternalMountPoints
                                 FileSystemType* type,
                                 base::FilePath* path) const OVERRIDE;
   virtual FileSystemURL CrackURL(const GURL& url) const OVERRIDE;
+  virtual FileSystemURL CrackFileSystemURL(
+      const FileSystemURL& url) const OVERRIDE;
   virtual FileSystemURL CreateCrackedFileSystemURL(
       const GURL& origin,
       FileSystemType type,
       const base::FilePath& path) const OVERRIDE;
 
-  // Retrieves the remote file system proxy for the registered file system.
+ // Retrieves the remote file system proxy for the registered file system.
   // Returns NULL if there is no file system with the given name, or if the file
   // system does not have a remote file system proxy.
   RemoteFileSystemProxyInterface* GetRemoteFileSystemProxy(
@@ -105,7 +107,7 @@ class WEBKIT_STORAGE_EXPORT ExternalMountPoints
   //
   // Returned virtual_path will have normalized path separators.
   bool GetVirtualPath(const base::FilePath& absolute_path,
-                      base::FilePath* virtual_path);
+                      base::FilePath* virtual_path) const;
 
   // Returns the virtual root path that looks like /<mount_name>.
   base::FilePath CreateVirtualRootPath(const std::string& mount_name) const;