Send navigation_start to the browser in DidStartProvisionalLoad IPC

content/browser/frame_host/render_frame_host_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/frame_host/render_frame_host_impl.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/containers/hash_tables.h"
 #include "base/lazy_instance.h"
@@ skipping 786 matching lines @@
     UMA_HISTOGRAM_CUSTOM_TIMES("Navigation.UI_OnLoadComplete.Intent",
                                base::TimeTicks::Now() - ui_timestamp,
                                base::TimeDelta::FromMilliseconds(10),
                                base::TimeDelta::FromMinutes(10), 100);
   }
   // This message is only sent for top-level frames. TODO(avi): when frame tree
   // mirroring works correctly, add a check here to enforce it.
   delegate_->DocumentOnLoadCompleted(this);
 }
 
-void RenderFrameHostImpl::OnDidStartProvisionalLoadForFrame(const GURL& url) {
-  frame_tree_node_->navigator()->DidStartProvisionalLoad(
-      this, url);
+void RenderFrameHostImpl::OnDidStartProvisionalLoadForFrame(
+    const GURL& url,
+    const base::TimeTicks& navigation_start) {
+  frame_tree_node_->navigator()->DidStartProvisionalLoad(this, url,
+                                                         navigation_start);
 }
 
 void RenderFrameHostImpl::OnDidFailProvisionalLoadWithError(
     const FrameHostMsg_DidFailProvisionalLoadWithError_Params& params) {
   if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableBrowserSideNavigation) &&
       navigation_handle_) {
     navigation_handle_->set_net_error_code(
         static_cast<net::Error>(params.error_code));
   }
@@ skipping 119 matching lines @@
   if (navigation_handle_ &&
       navigation_handle_->GetURL() != validated_params.url) {
     navigation_handle_.reset();
   }
 
   // Synchronous renderer-initiated navigations will send a
   // DidCommitProvisionalLoad IPC without a prior DidStartProvisionalLoad
   // message.
   if (!navigation_handle_) {
     navigation_handle_ = NavigationHandleImpl::Create(
-        validated_params.url, frame_tree_node_);
+        validated_params.url, frame_tree_node_, base::TimeTicks::Now());

[nasko, 2015/11/13 21:52:54]

Why not the actual start time from the renderer process?

[Charlie Harrison, 2015/11/14 00:25:00]

We discussed this briefly over email, but I think to track same-page navigations
like this from the renderer, we would need to send the timestamp on commit IPCs
as well as provisional. Since these navigations are less important, I figured
that adding this additional timestamp and complexity would not be worth it until
a consumer wanted it.

   }
 
   accessibility_reset_count_ = 0;
   frame_tree_node()->navigator()->DidNavigate(this, validated_params);
 
   // For a top-level frame, there are potential security concerns associated
   // with displaying graphics from a previously loaded page after the URL in
   // the omnibar has been changed. It is unappealing to clear the page
   // immediately, but if the renderer is taking a long time to issue any
   // compositor output (possibly because of script deliberately creating this
@@ skipping 1464 matching lines @@
   if (src.parent_routing_id != -1)
     dst->parent_tree_id = RoutingIDToAXTreeID(src.parent_routing_id);
 }
 
 void RenderFrameHostImpl::ResetWebUI() {
   web_ui_type_ = WebUI::kNoWebUI;
   web_ui_.reset();
 }
 
 }  // namespace content