Remove implementation of Panels on OSes other than ChromeOS.

chrome/test/data/extensions/api_test/window_open/panel/test.js

-// 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.
-
-var panelWindowId = 0;
-var panelLoaded = false;
-
-// This function is called by the panel during the test run.
-function panelCallback() {
-  panelLoaded = true;
-  maybeReadyForTest();
-}
-
-function maybeReadyForTest() {
-  // The order of the two callbacks is not guaranteed.
-  if( panelWindowId === 0 || !panelLoaded)
-    return;
-
-  // We have now added a panel so the total counts is 2 (browser + panel).
-  chrome.test.assertEq(2, chrome.extension.getViews().length);
-  // Verify that we're able to get the view of the panel by its window id.
-  chrome.test.assertEq(1,
-      chrome.extension.getViews({"windowId": panelWindowId}).length);
-  chrome.test.notifyPass();
-}
-
-chrome.test.runTests([
-  function openPanel() {
-    chrome.test.listenOnce(chrome.windows.onCreated, function(window) {
-      chrome.test.assertTrue(window.width > 0);
-      chrome.test.assertTrue(window.height > 0);
-      chrome.test.assertEq("panel", window.type);
-      chrome.test.assertTrue(!window.incognito);
-    });
-    chrome.windows.create(
-        { 'url': chrome.extension.getURL('panel.html'), 'type': 'panel' },
-        function(win) {
-            chrome.test.assertEq('panel', win.type);
-            chrome.test.assertEq(true, win.alwaysOnTop);
-            panelWindowId = win.id;
-            // The panel will call back to us through panelCallback (above).
-            maybeReadyForTest();
-        });
-  }
-]);