PlzNavigate: preserve SourceLocation when navigating

third_party/WebKit/Source/web/WebDataSourceImpl.h

 /*
  * Copyright (C) 2009 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 55 matching lines @@
   bool replacesCurrentHistoryItem() const override;
   WebNavigationType navigationType() const override;
   ExtraData* getExtraData() const override;
   void setExtraData(ExtraData*) override;
   void setNavigationStartTime(double) override;
   void updateNavigation(double redirectStartTime,
                         double redirectEndTime,
                         double fetchStartTime,
                         bool hasRedirect) override;
   void setSubresourceFilter(WebDocumentSubresourceFilter*) override;
+  void setSourceLocation(const WebSourceLocation&) override;
+  void resetSourceLocation() override;
 
   static WebNavigationType toWebNavigationType(NavigationType);
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   WebDataSourceImpl(LocalFrame*,
                     const ResourceRequest&,
                     const SubstituteData&,
                     ClientRedirectPolicy);
   ~WebDataSourceImpl() override;
   void detachFromFrame() override;
   String debugName() const override { return "WebDataSourceImpl"; }
 
   // Mutable because the const getters will magically sync these to the
   // latest version from WebKit.
   mutable WrappedResourceRequest m_originalRequestWrapper;
   mutable WrappedResourceRequest m_requestWrapper;
   mutable WrappedResourceResponse m_responseWrapper;
 
   std::unique_ptr<ExtraData> m_extraData;
 };
 
 }  // namespace blink
 
 #endif  // WebDataSourceImpl_h