Remove BackForwardClient, cleanup starting a history navigation

Source/web/WebViewImpl.h

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 29 matching lines @@
 #include "public/platform/WebGestureCurveTarget.h"
 #include "public/platform/WebLayer.h"
 #include "public/platform/WebPoint.h"
 #include "public/platform/WebRect.h"
 #include "public/platform/WebSize.h"
 #include "public/platform/WebString.h"
 #include "public/platform/WebVector.h"
 #include "public/web/WebInputEvent.h"
 #include "public/web/WebNavigationPolicy.h"
 #include "public/web/WebView.h"
-#include "web/BackForwardClientImpl.h"
 #include "web/ChromeClientImpl.h"
 #include "web/ContextMenuClientImpl.h"
 #include "web/DragClientImpl.h"
 #include "web/EditorClientImpl.h"
 #include "web/InspectorClientImpl.h"
 #include "web/MediaKeysClientImpl.h"
 #include "web/PageOverlayList.h"
 #include "web/PageScaleConstraintsSet.h"
 #include "web/PageWidgetDelegate.h"
 #include "web/SpellCheckerClientImpl.h"
@@ skipping 542 matching lines @@
 
     WebViewClient* m_client; // Can be 0 (e.g. unittests, shared workers, etc.)
     WebAutofillClient* m_autofillClient;
     WebSpellCheckClient* m_spellCheckClient;
 
     ChromeClientImpl m_chromeClientImpl;
     ContextMenuClientImpl m_contextMenuClientImpl;
     DragClientImpl m_dragClientImpl;
     EditorClientImpl m_editorClientImpl;
     InspectorClientImpl m_inspectorClientImpl;
-    BackForwardClientImpl m_backForwardClientImpl;
     SpellCheckerClientImpl m_spellCheckerClientImpl;
     StorageClientImpl m_storageClientImpl;
 
     WebSize m_size;
     // If true, automatically resize the render view around its content.
     bool m_shouldAutoResize;
     // The lower bound on the size when auto-resizing.
     IntSize m_minAutoSize;
     // The upper bound on the size when auto-resizing.
     IntSize m_maxAutoSize;
@@ skipping 128 matching lines @@
     float m_topControlsLayoutHeight;
 };
 
 // We have no ways to check if the specified WebView is an instance of
 // WebViewImpl because WebViewImpl is the only implementation of WebView.
 DEFINE_TYPE_CASTS(WebViewImpl, WebView, webView, true, true);
 
 } // namespace blink
 
 #endif