Fix filesystem API file_handlers to work for drive on ChromeOS.

webkit/fileapi/file_system_context.h

Index: webkit/fileapi/file_system_context.h
diff --git a/webkit/fileapi/file_system_context.h b/webkit/fileapi/file_system_context.h
index 1a938e23c4bd8a0425dbe5fb4925f7ad12b655cb..766a3b8aa92005de9de2d292a42e03ca701f6e97 100644
--- a/webkit/fileapi/file_system_context.h
+++ b/webkit/fileapi/file_system_context.h
@@ -241,6 +241,17 @@ class WEBKIT_STORAGE_EXPORT FileSystemContext
   // returns the original url, without attempting to crack it.
   FileSystemURL CrackFileSystemURL(const FileSystemURL& url) const;
 
+  // If the url has underlying file system url, returns its mount type.
+  // Otherwise returns kFileSystemTypeUnknown.
+  FileSystemType GetUnderlyingMountType(const FileSystemURL& url) const;
+
+  // Converts full file path to a virtual path under mount point contained in
+  // one of the url crackers that support the passed mount type.
+  // Returns whether the path can be converted.
+  bool GetVirtualPath(FileSystemType mount_type,
+                      const base::FilePath& full_path,
+                      base::FilePath* virtual_path) const;
+
   // Returns the appropriate FileUtil instance for the given |type|.
   // This may return NULL if it is given an invalid type or the filesystem
   // does not support synchronous file operations.