Creates BrowserTabStripTracker to consolidate common code

chrome/browser/extensions/api/web_navigation/web_navigation_api.cc

 // Copyright (c) 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.
 
 // Implements the Chrome Extensions WebNavigation API.
 
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api.h"
 
 #include "base/lazy_instance.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ skipping 56 matching lines @@
     const GURL& target_url)
     : source_web_contents(source_web_contents),
       source_frame_host(source_frame_host),
       target_web_contents(target_web_contents),
       target_url(target_url) {
 }
 
 WebNavigationEventRouter::PendingWebContents::~PendingWebContents() {}
 
 WebNavigationEventRouter::WebNavigationEventRouter(Profile* profile)
-    : profile_(profile) {
+    : profile_(profile), browser_tab_strip_tracker_(this, this, nullptr) {
   CHECK(registrar_.IsEmpty());
   registrar_.Add(this,
                  chrome::NOTIFICATION_RETARGETING,
                  content::NotificationService::AllSources());
   registrar_.Add(this,
                  chrome::NOTIFICATION_TAB_ADDED,
                  content::NotificationService::AllSources());
   registrar_.Add(this,
                  content::NOTIFICATION_WEB_CONTENTS_DESTROYED,
                  content::NotificationService::AllSources());
 
-  BrowserList::AddObserver(this);
-  for (chrome::BrowserIterator it; !it.done(); it.Next())
-    OnBrowserAdded(*it);
+  browser_tab_strip_tracker_.Init(
+      BrowserTabStripTracker::InitWith::ALL_BROWERS);
 }
 
 WebNavigationEventRouter::~WebNavigationEventRouter() {
-  for (chrome::BrowserIterator it; !it.done(); it.Next())
-    OnBrowserRemoved(*it);
-  BrowserList::RemoveObserver(this);
 }
 
-void WebNavigationEventRouter::OnBrowserAdded(Browser* browser) {
-  if (!profile_->IsSameProfile(browser->profile()))
-    return;
-  browser->tab_strip_model()->AddObserver(this);
-}
-
-void WebNavigationEventRouter::OnBrowserRemoved(Browser* browser) {
-  if (!profile_->IsSameProfile(browser->profile()))
-    return;
-  browser->tab_strip_model()->RemoveObserver(this);
+bool WebNavigationEventRouter::ShouldTrackBrowser(Browser* browser) {
+  return profile_->IsSameProfile(browser->profile());
 }
 
 void WebNavigationEventRouter::TabReplacedAt(
     TabStripModel* tab_strip_model,
     content::WebContents* old_contents,
     content::WebContents* new_contents,
     int index) {
   WebNavigationTabObserver* tab_observer =
       WebNavigationTabObserver::Get(old_contents);
   if (!tab_observer) {
@@ skipping 505 matching lines @@
   return g_factory.Pointer();
 }
 
 void WebNavigationAPI::OnListenerAdded(const EventListenerInfo& details) {
   web_navigation_event_router_.reset(new WebNavigationEventRouter(
       Profile::FromBrowserContext(browser_context_)));
   EventRouter::Get(browser_context_)->UnregisterObserver(this);
 }
 
 }  // namespace extensions