Add more navigation tracing to RenderFrameHost and NavigationRequest.

content/browser/frame_host/navigation_request.h

Index: content/browser/frame_host/navigation_request.h
diff --git a/content/browser/frame_host/navigation_request.h b/content/browser/frame_host/navigation_request.h
index 095b77f53be296d0f25bc142816eb584d9934f7f..95490aa236374583625ffde0f3817f7cd18e1849 100644
--- a/content/browser/frame_host/navigation_request.h
+++ b/content/browser/frame_host/navigation_request.h
@@ -135,6 +135,8 @@ class CONTENT_EXPORT NavigationRequest : public NavigationURLLoaderDelegate {
   bool may_transfer() const { return may_transfer_; }
 
   void SetWaitingForRendererResponse() {
+    TRACE_EVENT_ASYNC_STEP_INTO0("navigation", "NavigationRequest", this,
+                                 "WaitingForRendererResponse");
     DCHECK(state_ == NOT_STARTED);
     state_ = WAITING_FOR_RENDERER_RESPONSE;

[Charlie Reis, 2017/04/28 00:30:52]

Minor nit: This implementation probably belongs in the .cc file at this point,
with the extra code.  (It's already not hacker_style(), so it seems a bit odd to
have it inlined anyway.)

[nasko, 2017/04/28 14:01:53]

Done.

   }