Make extension browser tests always run as though they're on dev channel.

chrome/browser/extensions/extension_browsertest.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.
 
 #include "chrome/browser/extensions/extension_browsertest.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/file_path.h"
@@ skipping 29 matching lines @@
 
 using extensions::Extension;
 using extensions::ExtensionCreator;
 
 ExtensionBrowserTest::ExtensionBrowserTest()
     : loaded_(false),
       installed_(false),
       extension_installs_observed_(0),
       extension_load_errors_observed_(0),
       target_page_action_count_(-1),
-      target_visible_page_action_count_(-1) {
+      target_visible_page_action_count_(-1),
+      current_channel_(chrome::VersionInfo::CHANNEL_DEV) {
   EXPECT_TRUE(temp_dir_.CreateUniqueTempDir());
   AppShortcutManager::SetShortcutCreationDisabledForTesting(true);
 }
 
 ExtensionBrowserTest::~ExtensionBrowserTest() {
   AppShortcutManager::SetShortcutCreationDisabledForTesting(false);
 }
 
 void ExtensionBrowserTest::SetUpCommandLine(CommandLine* command_line) {
   PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir_);
@@ skipping 611 matching lines @@
     case content::NOTIFICATION_LOAD_STOP:
       VLOG(1) << "Got LOAD_STOP notification.";
       MessageLoopForUI::current()->Quit();
       break;
 
     default:
       NOTREACHED();
       break;
   }
 }