Remove WebContentsObserver::ProvisionalChangeToMainFrameUrl and all the code supporting it.

content/browser/frame_host/render_frame_host_impl.cc

Index: content/browser/frame_host/render_frame_host_impl.cc
diff --git a/content/browser/frame_host/render_frame_host_impl.cc b/content/browser/frame_host/render_frame_host_impl.cc
index cedff4b604a92756a715e4e9733d6998900447b6..585fb225282f1448ba825bd80d6f1509fe1bc9d8 100644
--- a/content/browser/frame_host/render_frame_host_impl.cc
+++ b/content/browser/frame_host/render_frame_host_impl.cc
@@ -347,8 +347,6 @@ bool RenderFrameHostImpl::OnMessageReceived(const IPC::Message &msg) {
                         OnDidStartProvisionalLoadForFrame)
     IPC_MESSAGE_HANDLER(FrameHostMsg_DidFailProvisionalLoadWithError,
                         OnDidFailProvisionalLoadWithError)
-    IPC_MESSAGE_HANDLER(FrameHostMsg_DidRedirectProvisionalLoad,
-                        OnDidRedirectProvisionalLoad)
     IPC_MESSAGE_HANDLER(FrameHostMsg_DidFailLoadWithError,
                         OnDidFailLoadWithError)
     IPC_MESSAGE_HANDLER_GENERIC(FrameHostMsg_DidCommitProvisionalLoad,
@@ -646,14 +644,6 @@ void RenderFrameHostImpl::OnDidFailLoadWithError(
       this, validated_url, error_code, error_description);
 }
 
-void RenderFrameHostImpl::OnDidRedirectProvisionalLoad(
-    int32 page_id,
-    const GURL& source_url,
-    const GURL& target_url) {
-  frame_tree_node_->navigator()->DidRedirectProvisionalLoad(
-      this, page_id, source_url, target_url);
-}
-
 // Called when the renderer navigates.  For every frame loaded, we'll get this
 // notification containing parameters identifying the navigation.
 //