Convert NavigationMetricsRecorder to use the new navigation callbacks.

content/browser/frame_host/navigation_handle_impl.h

Index: content/browser/frame_host/navigation_handle_impl.h
diff --git a/content/browser/frame_host/navigation_handle_impl.h b/content/browser/frame_host/navigation_handle_impl.h
index 65ce406d3021ded9f47adffc8d8d957c1d3ec513..7ec6656dfc546e8422e78f5a22b3b2054841d5d8 100644
--- a/content/browser/frame_host/navigation_handle_impl.h
+++ b/content/browser/frame_host/navigation_handle_impl.h
@@ -111,6 +111,7 @@ class CONTENT_EXPORT NavigationHandleImpl : public NavigationHandle {
   bool IsSamePage() override;
   bool HasCommitted() override;
   bool IsErrorPage() override;
+  const GURL& GetPreviousURL() override;
   net::HostPortPair GetSocketAddress() override;
   const net::HttpResponseHeaders* GetResponseHeaders() override;
   net::HttpResponseInfo::ConnectionInfo GetConnectionInfo() override;
@@ -280,6 +281,7 @@ class CONTENT_EXPORT NavigationHandleImpl : public NavigationHandle {
   void DidCommitNavigation(
       const FrameHostMsg_DidCommitProvisionalLoad_Params& params,
       bool same_page,
+      const GURL& previous_url,
       RenderFrameHostImpl* render_frame_host);
 
   // Called during commit. Takes ownership of the embedder's NavigationData
@@ -461,6 +463,7 @@ class CONTENT_EXPORT NavigationHandleImpl : public NavigationHandle {
   GURL searchable_form_url_;
   std::string searchable_form_encoding_;
 
+  GURL previous_url_;
   GURL base_url_;
   net::HostPortPair socket_address_;