(DEPRECATED) Send navigation_start to browser process in DidStartProvisionalLoad

content/common/navigation_params.h

 // Copyright 2014 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_COMMON_NAVIGATION_PARAMS_H_
 #define CONTENT_COMMON_NAVIGATION_PARAMS_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 109 matching lines @@
 // following a renderer-initiated navigation request.
 struct CONTENT_EXPORT BeginNavigationParams {
   // TODO(clamy): See if it is possible to reuse this in
   // ResourceMsg_Request_Params.
   BeginNavigationParams();
   BeginNavigationParams(std::string method,
                         std::string headers,
                         int load_flags,
                         bool has_user_gesture,
                         bool skip_service_worker,
-                        RequestContextType request_context_type);
+                        RequestContextType request_context_type,
+                        double renderer_navigation_start);

[clamy, 2015/10/28 12:40:01]

Instead of adding a new value in BeginNavigationParams, I suggest we move
browser_navigation_start out of the RequestNavigationParams into the
CommonNavigationParams and rename it navigation_start.

Whether in PlzNavigate or in browser-initiated navigations in the current
architecture, we always initialize a CommonNavigationParams at the beginning of
the navigation. For renderer-initiated navigations in the current architecture,
it's initialized when we create the provisional DataSource for the frame, which
(I think) corresponds to the start of the navigation.

 
   // The request method: GET, POST, etc.
   std::string method;
 
   // Additional HTTP request headers.
   std::string headers;
 
   // net::URLRequest load flags (net::LOAD_NORMAL) by default).
   int load_flags;
 
   // True if the request was user initiated.
   bool has_user_gesture;
 
   // True if the ServiceWorker should be skipped.
   bool skip_service_worker;
 
   // Indicates the request context type.
   RequestContextType request_context_type;
+
+  // The time the navigation started in the renderer.
+  double renderer_navigation_start;
 };
 
 // Provided by the browser -----------------------------------------------------
 //
 // These structs are sent by the browser to the renderer to start/commit a
 // navigation depending on whether browser-side navigation is enabled.
 // Parameters used both in the current architecture and PlzNavigate should be
 // put in RequestNavigationParams.  Parameters only used by the current
 // architecture should go in StartNavigationParams.
 
@@ skipping 146 matching lines @@
   ~NavigationParams();
 
   CommonNavigationParams common_params;
   StartNavigationParams start_params;
   RequestNavigationParams request_params;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_NAVIGATION_PARAMS_H_