Initial stub version of Async Clipboard API

third_party/WebKit/Source/core/frame/NavigatorClipboard.cpp

+// 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.
+
+#include "core/frame/NavigatorClipboard.h"
+
+#include "core/clipboard/Clipboard.h"
+#include "core/dom/Document.h"
+#include "core/frame/LocalFrame.h"
+
+namespace blink {
+
+Clipboard* NavigatorClipboard::clipboard(ScriptState* script_state,
+                                         Navigator& navigator) {
+  NavigatorClipboard* supplement = static_cast<NavigatorClipboard*>(
+      Supplement<Navigator>::From(navigator, SupplementName()));
+  if (!supplement) {
+    supplement = new NavigatorClipboard(navigator);
+    ProvideTo(navigator, SupplementName(), supplement);
+  }
+
+  return supplement->clipboard_;
+}
+
+DEFINE_TRACE(NavigatorClipboard) {
+  visitor->Trace(clipboard_);
+  Supplement<Navigator>::Trace(visitor);
+}
+
+NavigatorClipboard::NavigatorClipboard(Navigator& navigator)
+    : Supplement<Navigator>(navigator) {
+  clipboard_ =
+      new Clipboard(GetSupplementable()->GetFrame()
+                        ? GetSupplementable()->GetFrame()->GetDocument()
+                        : nullptr);

[dcheng, 2017/06/14 18:56:22]

Btw, can we combine Clipboard and NavigatorClipboard? It doesn't seem like other
supplements (such as NavigatorPlugins) split it into two.

[garykac, 2017/06/29 01:37:26]

We have 2 separate IDL files (Navigator supplement and the actual clipboard).
While we could combine them, I believe that it is cleaner to leave them
separate.

Let's follow up on this when you get back from vacation and I can do a follow-up
cl if necessary.

[dcheng1, 2017/06/29 05:08:17]

OK, that's a good reason =)

+}
+
+const char* NavigatorClipboard::SupplementName() {
+  return "NavigatorClipboard";
+}
+
+}  // namespace blink