PlzNavigate: properly execute BeforeUnload on renderer initiated navigations

third_party/WebKit/Source/web/WebRemoteFrameImpl.h

 // 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 WebRemoteFrameImpl_h
 #define WebRemoteFrameImpl_h
 
 #include "core/frame/RemoteFrame.h"
 #include "platform/heap/SelfKeepAlive.h"
 #include "public/web/WebRemoteFrame.h"
@@ skipping 28 matching lines @@
     WebSize scrollOffset() const override;
     void setScrollOffset(const WebSize&) override;
     WebSize contentsSize() const override;
     bool hasVisibleContent() const override;
     WebRect visibleContentRect() const override;
     bool hasHorizontalScrollbar() const override;
     bool hasVerticalScrollbar() const override;
     WebView* view() const override;
     WebDocument document() const override;
     WebPerformance performance() const override;
-    bool dispatchBeforeUnloadEvent() override;
     void dispatchUnloadEvent() override;
     void executeScript(const WebScriptSource&) override;
     void executeScriptInIsolatedWorld(
         int worldID, const WebScriptSource* sources, unsigned numSources,
         int extensionGroup) override;
     void setIsolatedWorldSecurityOrigin(int worldID, const WebSecurityOrigin&) override;
     void setIsolatedWorldContentSecurityPolicy(int worldID, const WebString&) override;
     void addMessageToConsole(const WebConsoleMessage&) override;
     void collectGarbage() override;
     v8::Local<v8::Value> executeScriptAndReturnValue(
@@ skipping 127 matching lines @@
     // Accomplish that by keeping a self-referential Persistent<>. It is
     // cleared upon close().
     SelfKeepAlive<WebRemoteFrameImpl> m_selfKeepAlive;
 };
 
 DEFINE_TYPE_CASTS(WebRemoteFrameImpl, WebFrame, frame, frame->isWebRemoteFrame(), frame.isWebRemoteFrame());
 
 } // namespace blink
 
 #endif // WebRemoteFrameImpl_h