[Extensions] Clean up renderer channel-related code

extensions/shell/test/shell_test.cc

 // Copyright 2014 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 "extensions/shell/test/shell_test.h"
 
 #include "base/base_paths.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "build/build_config.h"
+#include "components/version_info/version_info.h"
 #include "content/public/common/content_switches.h"
 #include "extensions/browser/extension_system.h"
 #include "extensions/shell/browser/desktop_controller.h"
 #include "extensions/shell/browser/shell_content_browser_client.h"
 #include "extensions/shell/browser/shell_extension_system.h"
 
 namespace extensions {
 
-AppShellTest::AppShellTest() : browser_context_(NULL), extension_system_(NULL) {
+AppShellTest::AppShellTest()
+    : browser_context_(nullptr),
+      extension_system_(nullptr),
+      // Default channel is STABLE but override with UNKNOWN so that unlaunched
+      // or incomplete APIs can write tests.
+      current_channel_(version_info::Channel::UNKNOWN) {
 #if defined(OS_MACOSX)
   // TODO(phajdan.jr): Make browser tests self-contained on Mac; remove this.
   // Set up the application path as though we we are inside the App Shell.app
   // bundle, rather than the top-level extensions_browsertests, because we
   // make many assumptions about where the executable is located.
   base::FilePath app_shell_path;
   CHECK(PathService::Get(base::FILE_EXE, &app_shell_path));
   app_shell_path = app_shell_path.DirName();
   app_shell_path = app_shell_path.Append(
       FILE_PATH_LITERAL("App Shell.app/Contents/MacOS/App Shell"));
@@ skipping 25 matching lines @@
 
   RunTestOnMainThread();
 
   TearDownOnMainThread();
 
   // Clean up the app window.
   DesktopController::instance()->CloseAppWindows();
 }
 
 }  // namespace extensions