Remove a bunch of provisionalDataSource() usage.

content/public/renderer/render_frame_observer.h

Index: content/public/renderer/render_frame_observer.h
diff --git a/content/public/renderer/render_frame_observer.h b/content/public/renderer/render_frame_observer.h
index 7b4eeb795b5d20bf8316a7262b8434f64766ad45..1d135d23636a5ef320e9f01ff4d47920c1013fec 100644
--- a/content/public/renderer/render_frame_observer.h
+++ b/content/public/renderer/render_frame_observer.h
@@ -15,6 +15,7 @@
 #include "v8/include/v8.h"
 
 namespace blink {
+class WebDataSource;
 class WebFormElement;
 class WebFrame;
 class WebNode;
@@ -55,7 +56,7 @@ class CONTENT_EXPORT RenderFrameObserver : public IPC::Listener,
   virtual void DidCreateDocumentElement() {}
   virtual void DidCommitProvisionalLoad(bool is_new_navigation,
                                         bool is_same_page_navigation) {}
-  virtual void DidStartProvisionalLoad() {}
+  virtual void DidStartProvisionalLoad(blink::WebDataSource* datasource) {}
   virtual void DidFailProvisionalLoad(const blink::WebURLError& error) {}
   virtual void DidFinishLoad() {}
   virtual void DidFinishDocumentLoad() {}