Remove implementation of Panels on OSes other than ChromeOS.

chrome/browser/extensions/window_open_interactive_apitest.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 "base/command_line.h"
 #include "build/build_config.h"
 #include "chrome/browser/extensions/extension_apitest.h"
-#include "chrome/common/chrome_switches.h"
-
-class WindowOpenPanelTest : public ExtensionApiTest {
-  void SetUpCommandLine(base::CommandLine* command_line) override {
-    ExtensionApiTest::SetUpCommandLine(command_line);
-    command_line->AppendSwitch(switches::kEnablePanels);
-  }
-};
 
 // http://crbug.com/253417 for NDEBUG
 #if (defined(OS_WIN) || defined(OS_MACOSX)) && defined(NDEBUG)
 // Focus test fails if there is no window manager on Linux.
-IN_PROC_BROWSER_TEST_F(WindowOpenPanelTest, WindowOpenFocus) {
+IN_PROC_BROWSER_TEST_F(ExtensionApiTest, WindowOpenFocus) {
   ASSERT_TRUE(RunExtensionTest("window_open/focus")) << message_;
 }
 #endif