Correctly record and pass around navigation start time.

components/web_view/frame.cc

Index: components/web_view/frame.cc
diff --git a/components/web_view/frame.cc b/components/web_view/frame.cc
index 0670977c375c838b7756bbb99919b45bdb0b9f2e..3b8e89a9f40bcacecba5e04ae789ca0a38d40fad 100644
--- a/components/web_view/frame.cc
+++ b/components/web_view/frame.cc
@@ -96,7 +96,8 @@ Frame::~Frame() {
 
 void Frame::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) {
   {
     // Set the FrameClient to null so that we don't notify the client of the
     // add before OnConnect().
@@ -106,6 +107,7 @@ void Frame::Init(Frame* parent,
       parent->Add(this);
   }
 
+  navigation_start_time_ = navigation_start_time;
   const ClientType client_type = frame_request.is_pending()
                                      ? ClientType::NEW_CHILD_FRAME
                                      : ClientType::EXISTING_FRAME_NEW_APP;
@@ -205,7 +207,9 @@ void Frame::InitClient(ClientType client_type,
     frame_client_->OnConnect(
         nullptr, tree_->change_id(), id_, mojom::VIEW_CONNECT_TYPE_USE_NEW,
         mojo::Array<mojom::FrameDataPtr>(),
+        navigation_start_time_.ToInternalValue(),
         base::Bind(&OnConnectAck, base::Passed(&data_and_binding)));
+    navigation_start_time_ = base::TimeTicks();
   } else {
     std::vector<const Frame*> frames;
     tree_->root()->BuildFrameTree(&frames);
@@ -224,8 +228,9 @@ void Frame::InitClient(ClientType client_type,
         client_type == ClientType::EXISTING_FRAME_SAME_APP
             ? mojom::VIEW_CONNECT_TYPE_USE_EXISTING
             : mojom::VIEW_CONNECT_TYPE_USE_NEW,
-        array.Pass(),
+        array.Pass(), navigation_start_time_.ToInternalValue(),
         base::Bind(&OnConnectAck, base::Passed(&data_and_binding)));
+    navigation_start_time_ = base::TimeTicks();
     tree_->delegate_->DidStartNavigation(this);
 
     // We need |embedded_connection_id_| is order to validate requests to
@@ -342,6 +347,8 @@ void Frame::StartNavigate(mojo::URLRequestPtr request) {
     return;
   }
 
+  navigation_start_time_ =

[sky, 2015/10/14 22:46:24]

Does navigation_start_time_ need to be a member? Can it be passed to
OnCanNavigationFrame?

[yzshen1, 2015/10/14 22:59:15]

In that case we also need to pass it to ChangeClient, OnWillNavigateAck,
InitClient. I feel that it seems easier to have a member variable. What do you
think? Thanks!

[sky, 2015/10/14 23:08:36]

The problem with the member is that it's easy to accidentally reset and end up
using the wrong value. By passing the value around it's clear the value
corresponds to a particular navigation.

[yzshen1, 2015/10/15 00:05:10]

Done.

+      base::TimeTicks::FromInternalValue(request->originating_time_ticks);
   // Drop any pending navigation requests.
   navigate_weak_ptr_factory_.InvalidateWeakPtrs();