[page_load_metrics] Get navigation_start from NavigationHandle

content/public/browser/navigation_handle.h

 // Copyright 2015 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_NAVIGATION_HANDLE_H_
 #define CONTENT_PUBLIC_BROWSER_NAVIGATION_HANDLE_H_
 
 #include "content/common/content_export.h"
 #include "content/public/browser/navigation_throttle.h"
 #include "content/public/common/referrer.h"
@@ skipping 21 matching lines @@
   // when encountering a server redirect.
   virtual const GURL& GetURL() = 0;
 
   // Whether the navigation is taking place in the main frame or in a subframe.
   // This remains constant over the navigation lifetime.
   virtual bool IsInMainFrame() = 0;
 
   // The WebContents the navigation is taking place in.
   WebContents* GetWebContents();
 
+  // The time the navigation started, recorded either in the renderer or browser

[clamy, 2015/11/09 13:09:53]

nit: in the browser process...

[Charlie Harrison, 2015/11/09 18:45:10]

Can you clarify this comment?

[kinuko, 2015/11/12 20:35:11]

"... in the renderer or in the browser process" I guess.

+  // process. Corresponds to Navigation Timing API Standard.

[clamy, 2015/11/09 13:09:53]

nit: the Navigation Timing API Standard?

[Charlie Harrison, 2015/11/09 18:45:10]

Done.

+  virtual const base::TimeTicks& GetNavigationStart() = 0;
+
   // Parameters available at network request start time ------------------------
   //
   // The following parameters are only available when the network request is
   // made for the navigation (or at commit time if no network request is made).
   // This corresponds to NavigationThrottle::WillSendRequest. They should not
   // be queried before that.
 
   // Whether the navigation is a POST or a GET. This may change during the
   // navigation when encountering a server redirect.
   virtual bool IsPost() = 0;
@@ skipping 71 matching lines @@
   virtual NavigationThrottle::ThrottleCheckResult
   CallWillRedirectRequestForTesting(const GURL& new_url,
                                     bool new_method_is_post,
                                     const GURL& new_referrer_url,
                                     bool new_is_external_protocol) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_NAVIGATION_HANDLE_H_