Prerender Instant search base url on omnibox focus event

chrome/browser/ui/browser.cc

 // Copyright 2012 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 "chrome/browser/ui/browser.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #endif  // defined(OS_WIN)
@@ skipping 898 matching lines @@
 
   SessionService* session_service =
       SessionServiceFactory::GetForProfile(profile_);
   if (session_service) {
     session_service->TabInserted(contents);
     int new_active_index = tab_strip_model_->active_index();
     if (index < new_active_index)
       session_service->SetSelectedTabInWindow(session_id(),
                                               new_active_index);
   }
+
+  if (instant_controller_)
+    instant_controller_->TabInsertedAt(contents, index, foreground);

[kmadhusu, 2014/06/17 18:29:35]

As per our discussion, you are doing this to submit a prerender request when an
user adds a NTP. This only fixes the "Add new tab" workflow. This solution will
not work for the following use case:

1. Open a new tab (Tab_1) (This will submit a prerender request for Tab_1)
2. Open another new tab (Tab_2). (This will cancel the prerender request for
Tab_1 and submit a prerender request for Tab_2).
3. Switch to Tab_1  (This will cancel the prerender request for Tab_2 but will
not submit a prerender request for Tab_1 which we should have done because the
omnibox has focus).

[sidharthms, 2014/06/17 21:52:24]

Done.

 }
 
 void Browser::TabClosingAt(TabStripModel* tab_strip_model,
                            WebContents* contents,
                            int index) {
   fullscreen_controller_->OnTabClosing(contents);
   SessionService* session_service =
       SessionServiceFactory::GetForProfile(profile_);
   if (session_service)
     session_service->TabClosing(contents);
@@ skipping 1488 matching lines @@
   if (contents && !allow_js_access) {
     contents->web_contents()->GetController().LoadURL(
         target_url,
         content::Referrer(),
         content::PAGE_TRANSITION_LINK,
         std::string());  // No extra headers.
   }
 
   return contents != NULL;
 }