Fix flakiness by removing GetLastActive from extension browser tests.

chrome/browser/extensions/extension_browsertest.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_BROWSERTEST_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_BROWSERTEST_H_
 #pragma once
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/scoped_temp_dir.h"
 #include "chrome/test/base/in_process_browser_test.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_types.h"
+#include "content/public/browser/web_contents.h"
 
 namespace extensions {
 class Extension;
 }
 
 // Base class for extension browser tests. Provides utilities for loading,
 // unloading, and installing extensions.
 class ExtensionBrowserTest
     : public InProcessBrowserTest, public content::NotificationObserver {
  protected:
@@ skipping 100 matching lines @@
   void WaitForExtensionLoad();
 
   // Waits for an extension load error. Returns true if the error really
   // happened.
   bool WaitForExtensionLoadError();
 
   // Wait for the specified extension to crash. Returns true if it really
   // crashed.
   bool WaitForExtensionCrash(const std::string& extension_id);
 
+  // Simulates a page calling window.open on an URL and waits for the
+  // navigation.
+  void OpenWindow(content::WebContents* contents,
+                  const GURL& url,
+                  bool newtab_process_should_equal_opener,
+                  content::WebContents** newtab_result);
+
+  // Simulates a page navigating itself to an URL and waits for the
+  // navigation.
+  void NavigateInRenderer(content::WebContents* contents, const GURL& url);
+
   // content::NotificationObserver
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
   bool loaded_;
   bool installed_;
 
   // test_data/extensions.
   FilePath test_data_dir_;
@@ skipping 30 matching lines @@
   // When waiting for page action count to change, we wait until it reaches this
   // value.
   int target_page_action_count_;
 
   // When waiting for visible page action count to change, we wait until it
   // reaches this value.
   int target_visible_page_action_count_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_BROWSERTEST_H_