Reduce calling count of UpdateAppState()

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 1896 matching lines @@
   if (!source)
     return;
 
   // Do some synchronous updates.
   if (changed_flags & content::INVALIDATE_TYPE_URL &&
       source == tab_strip_model_->GetActiveWebContents()) {
     // Only update the URL for the current tab. Note that we do not update
     // the navigation commands since those would have already been updated
     // synchronously by NavigationStateChanged.
     UpdateToolbar(false);
+
+    tab_strip_model_->UpdateWebContentsStateAt(
+        tab_strip_model_->GetIndexOfWebContents(source),
+        TabStripModelObserver::URL_CHANGING_ONLY);

[sky, 2013/09/11 02:09:58]

Your usage here is not entirely correct so that URL_CHANGING_ONLY becomes
misleading and error prone.

If BrowserStatusMonitor only cares about the url of the active tab it should be
able to monitor that directly.

+
     changed_flags &= ~content::INVALIDATE_TYPE_URL;
   }
   if (changed_flags & content::INVALIDATE_TYPE_LOAD) {
     // Update the loading state synchronously. This is so the throbber will
     // immediately start/stop, which gives a more snappy feel. We want to do
     // this for any tab so they start & stop quickly.
     tab_strip_model_->UpdateWebContentsStateAt(
         tab_strip_model_->GetIndexOfWebContents(source),
         TabStripModelObserver::LOADING_ONLY);
     // The status bubble needs to be updated during INVALIDATE_TYPE_LOAD too,
@@ skipping 373 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;
 }