Add Worker support for FileSystem API.

webkit/tools/test_shell/simple_file_system.cc

Index: webkit/tools/test_shell/simple_file_system.cc
diff --git a/webkit/tools/test_shell/simple_file_system.cc b/webkit/tools/test_shell/simple_file_system.cc
index 0b767587abc78333f9b78cf5092e31ea91b5d0b6..9134acc5254b81b7b69777883bc6d74679a9d4f9 100644
--- a/webkit/tools/test_shell/simple_file_system.cc
+++ b/webkit/tools/test_shell/simple_file_system.cc
@@ -83,7 +83,7 @@ class TestShellFileSystemCallbackDispatcher
     file_system_->RemoveCompletedOperation(request_id_);
   }
 
-  virtual void DidOpenFileSystem(const string16&, const FilePath&) {
+  virtual void DidOpenFileSystem(const std::string&, const FilePath&) {
     NOTREACHED();
   }