Add mojo service for CopylessPaste in Blink

third_party/WebKit/Source/modules/document_metadata/CopylessPasteServer.h

+// Copyright 2017 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 CopylessPasteServer_h
+#define CopylessPasteServer_h
+
+#include "modules/ModulesExport.h"
+#include "platform/heap/Persistent.h"
+#include "public/platform/modules/document_metadata/copyless_paste.mojom-blink.h"
+
+namespace blink {
+
+class LocalFrame;
+
+class MODULES_EXPORT CopylessPasteServer final
+    : public mojom::blink::CopylessPaste {
+ public:
+  explicit CopylessPasteServer(LocalFrame&);
+
+  static void bindMojoRequest(LocalFrame*, mojom::blink::CopylessPasteRequest);
+
+  void GetEntities(const GetEntitiesCallback&) override;
+
+ private:
+  WeakPersistent<LocalFrame> m_frame;

[dglazkov, 2017/03/30 17:52:50]

Could you help me understand why WeakPersistent is used here?

[wychen, 2017/03/30 18:00:30]

I followed other similar examples like:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/modules/instal...
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/modules/app_ba...
To be honest I don't understand this pattern very well.

+};
+
+}  // namespace blink
+
+#endif  // CopylessPasteServer_h