PlzNavigate: Invoke didStartProvisionalLoad() when the renderer initiates a navigation in startLoad(

third_party/WebKit/Source/core/loader/FrameLoader.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) Research In Motion Limited 2009. All rights reserved.
  * Copyright (C) 2011 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:
@@ skipping 249 matching lines @@
 
   void scheduleCheckCompleted();
 
   void detachDocumentLoader(Member<DocumentLoader>&);
 
   void upgradeInsecureRequest(ResourceRequest&, Document*) const;
 
   std::unique_ptr<TracedValue> toTracedValue() const;
   void takeObjectSnapshot() const;
 
+  DocumentLoader* createDocumentLoader(const ResourceRequest&,
+                                       const FrameLoadRequest&,
+                                       FrameLoadType,
+                                       NavigationType);
+
   Member<LocalFrame> m_frame;
   AtomicString m_requiredCSP;
 
   // FIXME: These should be std::unique_ptr<T> to reduce build times and
   // simplify header dependencies unless performance testing proves otherwise.
   // Some of these could be lazily created for memory savings on devices.
   mutable FrameLoaderStateMachine m_stateMachine;
 
   Member<ProgressTracker> m_progressTracker;
 
@@ skipping 46 matching lines @@
   SandboxFlags m_forcedSandboxFlags;
 
   bool m_dispatchingDidClearWindowObjectInMainWorld;
   bool m_protectProvisionalLoader;
   bool m_isNavigationHandledByClient;
 };
 
 }  // namespace blink
 
 #endif  // FrameLoader_h