Change other usages of .size() to .empty() when applicable.

chrome/browser/external_tab_container_win.cc

 // Copyright (c) 2011 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/external_tab_container_win.h"
 
 #include <string>
 
 #include "base/debug/trace_event.h"
 #include "base/i18n/rtl.h"
@@ skipping 898 matching lines @@
     return container;
   }
 
   NOTREACHED() << "Failed to find ExternalTabContainer for cookie: "
                << cookie;
   return NULL;
 }
 
 void ExternalTabContainer::SetEnableExtensionAutomation(
     const std::vector<std::string>& functions_enabled) {
-  if (functions_enabled.size() > 0) {
+  if (!functions_enabled.empty()) {
     if (!tab_contents_.get()) {
       NOTREACHED() << "Being invoked via tab so should have TabContents";
       return;
     }
 
     AutomationExtensionFunction::Enable(tab_contents_->tab_contents(),
                                         functions_enabled);
     enabled_extension_automation_ = true;
   } else {
     AutomationExtensionFunction::Disable();
@@ skipping 192 matching lines @@
 
   if (disposition == CURRENT_TAB) {
     DCHECK(route_all_top_level_navigations_);
     disposition = NEW_FOREGROUND_TAB;
   }
   ExternalTabContainer::OpenURLFromTab(source, url, referrer, disposition,
                                        transition);
   // support only one navigation for a dummy tab before it is killed.
   ::DestroyWindow(GetNativeView());
 }