Implement the new wallpaper manager launcher window.

chrome/browser/resources/chromeos/wallpaper_manager/js/background.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.
+
+function WindowStateManager() {
+  this.savedWindow = [];
+}
+
+/**
+ * Minimize all opening windows and save their states.
+ */
+WindowStateManager.prototype.saveStates = function() {
+  var focusedWindowId;
+  chrome.windows.getLastFocused(function(focusedWindow) {
+    focusedWindowId = focusedWindow.id;
+  });
+  this.savedWindow = [];
+  var self = this;
+  chrome.windows.getAll(null, function(windows) {
+    for (var i in windows) {
+      if (windows[i].state != 'minimized')
+        self.savedWindow.push(windows[i]);
+      if (windows[i].id != focusedWindowId)
+        chrome.windows.update(windows[i].id, {'state': 'minimized'},
+                              function() {});
+    }
+  });
+};
+
+/**
+ * Restore the states of all windows.
+ */
+WindowStateManager.prototype.restoreStates = function() {
+  var self = this;
+  chrome.windows.getAll(null, function(windows) {
+    for (var i in windows) {
+      for (var j in self.savedWindow) {

[flackr, 2012/07/06 12:28:53]

You can probably avoid the need for a background page if you just send window
state updates for every window you remembered rather than wait for the
asynchronous window list to come back. I think it wouldn't matter if you sent an
update for a window id which no longer existed, and then the entire function
would be synchronous and could run in the page rather than a background page.

[bshe, 2012/07/06 18:58:06]

Done. Also added a focus event listener. So when the wallpaper manager get
focused, all opened windows should minimize.

On 2012/07/06 12:28:53, flackr wrote:

+        if (windows[i].id == self.savedWindow[j].id) {
+          var state = self.savedWindow[j].state;
+          chrome.windows.update(windows[i].id, {'state': state},
+                                function() {});
+        }
+      }
+    }
+  });
+};
+
+var windowStateManager = new WindowStateManager();