introduce DocumentParserClient to receive parser stopped notification

Source/core/dom/DocumentParserClient.h

Index: Source/core/dom/DocumentParserClient.h
diff --git a/Source/core/dom/DocumentParserClient.h b/Source/core/dom/DocumentParserClient.h
new file mode 100644
index 0000000000000000000000000000000000000000..38cc39bc9017c8ed33bb9f4e15c5439f559c6352
--- /dev/null
+++ b/Source/core/dom/DocumentParserClient.h
@@ -0,0 +1,23 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef DocumentParserClient_h
+#define DocumentParserClient_h
+
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+class DocumentParserClient : public WillBeGarbageCollectedMixin {
+public:
+    // This callback is called when all data pushed to parser has been consumed.
+    virtual void notifyParserStopped() = 0;
+
+protected:
+    DocumentParserClient() { }
+};
+
+} // namespace blink
+
+#endif // DocumentParserClient_h