Why this CL triggers an OilPan crash.

third_party/WebKit/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 83 matching lines @@
 class WebSettingsImpl;
 class WebViewScheduler;
 
 class WEB_EXPORT WebViewImpl final
     : NON_EXPORTED_BASE(public WebViewBase),
       NON_EXPORTED_BASE(public WebGestureCurveTarget),
       public PageWidgetEventHandler,
       public WebScheduler::InterventionReporter,
       public WebViewScheduler::WebViewSchedulerSettings {
  public:
-  static WebViewBase* Create(WebViewClient*, WebPageVisibilityState);
+  static WebViewBase* Create(WebViewClient*,
+                             WebPageVisibilityState,
+                             int browsing_instance_id);
 
   // WebWidget methods:
   void Close() override;
   WebSize Size() override;
   void Resize(const WebSize&) override;
   void ResizeVisualViewport(const WebSize&) override;
   void DidEnterFullscreen() override;
   void DidExitFullscreen() override;
 
   void SetSuppressFrameRequestsWorkaroundFor704763Only(bool) override;
@@ skipping 419 matching lines @@
   // TODO(lfg): Remove once WebViewFrameWidget is deleted.
   void ScheduleAnimationForWidget() override;
   bool GetCompositionCharacterBounds(WebVector<WebRect>&) override;
 
   void UpdateBaseBackgroundColor();
 
   friend class WebView;  // So WebView::Create can call our constructor
   friend class WebViewFrameWidget;
   friend class WTF::RefCounted<WebViewImpl>;
 
-  explicit WebViewImpl(WebViewClient*, WebPageVisibilityState);
+  explicit WebViewImpl(WebViewClient*,
+                       WebPageVisibilityState,
+                       int browsing_instance_id);
   ~WebViewImpl() override;
 
   void HideSelectPopup();
 
   HitTestResult HitTestResultForRootFramePos(const IntPoint&);
   HitTestResult HitTestResultForViewportPos(const IntPoint&);
 
   void ConfigureAutoResizeMode();
 
   void InitializeLayerTreeView();
@@ skipping 191 matching lines @@
   Persistent<ResizeViewportAnchor> resize_viewport_anchor_;
 };
 
 // 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