WebContentsObserver update for PlzNavigate methods

content/browser/frame_host/navigation_handle_impl.cc

Index: content/browser/frame_host/navigation_handle_impl.cc
diff --git a/content/browser/frame_host/navigation_handle_impl.cc b/content/browser/frame_host/navigation_handle_impl.cc
index 16ae7a2fe3245fb3bc7cebced866bf43d42b180b..42b729432cd0fbe7102697e46af0bc63dfc8b248 100644
--- a/content/browser/frame_host/navigation_handle_impl.cc
+++ b/content/browser/frame_host/navigation_handle_impl.cc
@@ -218,10 +218,7 @@ net::Error NavigationHandleImpl::GetNetErrorCode() {
 }
 
 RenderFrameHostImpl* NavigationHandleImpl::GetRenderFrameHost() {
-  // TODO(mkwst): Change this to check against 'READY_TO_COMMIT' once
-  // ReadyToCommitNavigation is available whether or not PlzNavigate is
-  // enabled. https://crbug.com/621856

[Ted C, 2016/12/28 20:00:21]

ah, the bug got fixed so you're just resolving the TODO it seems.  That threw me
off initially.

-  CHECK_GE(state_, WILL_PROCESS_RESPONSE)
+  CHECK_GE(state_, READY_TO_COMMIT)
       << "This accessor should only be called after a response has been "
          "delivered for processing.";
   return render_frame_host_;