Correctly record and pass around navigation start time.

components/web_view/frame.h

Index: components/web_view/frame.h
diff --git a/components/web_view/frame.h b/components/web_view/frame.h
index f0756df07bfe047dcdfd187caacdc70b7a748a2e..2dba0b26f99e63656cb37fab1bf6e6b74f39eba5 100644
--- a/components/web_view/frame.h
+++ b/components/web_view/frame.h
@@ -10,6 +10,7 @@
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
 #include "components/mus/public/cpp/types.h"
 #include "components/mus/public/cpp/view_observer.h"
 #include "components/web_view/public/interfaces/frame.mojom.h"
@@ -68,7 +69,8 @@ class Frame : public mus::ViewObserver, public mojom::Frame {
 
   void Init(Frame* parent,
             mojo::ViewTreeClientPtr view_tree_client,
-            mojo::InterfaceRequest<mojom::Frame> frame_request);
+            mojo::InterfaceRequest<mojom::Frame> frame_request,
+            base::TimeTicks navigation_start_time);
 
   // Walks the View tree starting at |view| going up returning the first
   // Frame that is associated with |view|. For example, if |view|
@@ -271,6 +273,8 @@ class Frame : public mus::ViewObserver, public mojom::Frame {
   // True if waiting on callback from FrameClient::OnWillNavigate().
   bool waiting_for_on_will_navigate_ack_;
 
+  base::TimeTicks navigation_start_time_;
+
   base::WeakPtrFactory<Frame> embed_weak_ptr_factory_;
 
   base::WeakPtrFactory<Frame> navigate_weak_ptr_factory_;