Switch the about:gpu implementation from an about handler to dom_ui....

chrome/browser/resources/gpu/tabswitcherview.js

+// Copyright (c) 2010 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.
+
+/**
+ * TabSwitcher is an implementation of View that handles tab switching.
+ *
+ *  +-----------------------------------+
+ *  | Tab1 / Tab2 / Tab3 / ..           |  <- tab handle view
+ *  +-----------------------------------+
+ *  |                                   |
+ *  |                                   |
+ *  |                                   |
+ *  |   stacked tab content areas       |
+ *  |   (only 1 is visible at a time)   |
+ *  |                                   |
+ *  |                                   |
+ *  |                                   |
+ *  +-----------------------------------+
+ *
+ * @parameter {!View} tabHandleView the view that contains the tab handles.
+ *
+ * @constructor
+ */
+function TabSwitcherView(tabHandleView) {
+  View.call(this);
+  this.tabHandleView_ = tabHandleView;
+  this.tabs_ = [];
+}
+
+inherits(TabSwitcherView, View);

[arv (Not doing code reviews), 2010/11/24 19:07:38]

Use the following pattern for inheritance (less code)

function TabSwitcherView(...) {
  ... 
}

TabSwitcherView.prototype = {
  __proto__: View.prototype,
  setGeometry: function(...) {
    ...
  },
  ...
};

+
+TabSwitcherView.prototype.setGeometry = function(left, top, width, height) {
+  TabSwitcherView.superClass_.setGeometry.call(this, left, top, width, height);
+
+  this.tabHandleView_.setGeometry(
+      left, top, width, this.tabHandleView_.getHeight());
+
+  var contentTop = this.tabHandleView_.getBottom();
+  var contentHeight = height - this.tabHandleView_.getHeight();
+
+  // Position each of the tabs content areas.
+  for (var i = 0; i < this.tabs_.length; ++i) {
+    var tab = this.tabs_[i];
+    tab.contentView.setGeometry(left, contentTop, width, contentHeight);
+  }
+};
+
+TabSwitcherView.prototype.show = function(isVisible) {

[arv (Not doing code reviews), 2010/11/24 19:07:38]

use a setter/getter

set visible(visible) {
  ...
},
get visible() {
  ...
},

+  TabSwitcherView.superClass_.show.call(this, isVisible);
+
+  this.tabHandleView_.show(isVisible);
+
+  var activeTab = this.findActiveTab();
+  if (activeTab)
+    activeTab.contentView.show(isVisible);
+};
+
+/**
+ * Adds a new tab (initially hidden).
+ *
+ * @param {String} id The ID for DOM node that will be made clickable to select
+ *                    this tab. This is also the ID we use to identify the
+ *                    "tab".
+ * @param {!View} view The tab's actual contents.
+ */
+TabSwitcherView.prototype.addTab = function(id, contentView, switchOnClick) {
+  var tab = new TabEntry(id, contentView);
+  this.tabs_.push(tab);
+
+  if (switchOnClick) {
+    // Attach a click handler, used to switch to the tab.
+    var self = this;
+    tab.getTabHandleNode().onclick = function() {

[arv (Not doing code reviews), 2010/11/24 19:07:38]

Use bind

tab.getTabHandleNode().onclick = this.switchToTab.bind(this, (id);

+      self.switchToTab(id);
+    };
+  }
+
+  // Start tabs off as hidden.
+  tab.contentView.show(false);
+};
+
+/**
+ * Returns the currently selected tab, or null if there is none.
+ * @returns {!TabEntry}
+ */
+TabSwitcherView.prototype.findActiveTab = function() {
+  for (var i = 0; i < this.tabs_.length; ++i) {
+    var tab = this.tabs_[i];
+    if (tab.active)
+      return tab;
+  }
+  return null;
+};
+
+/**
+ * Returns the tab with ID |id|.
+ * @returns {!TabEntry}
+ */
+TabSwitcherView.prototype.findTabById = function(id) {
+  for (var i = 0; i < this.tabs_.length; ++i) {

[arv (Not doing code reviews), 2010/11/24 19:07:38]

indexOf

+    var tab = this.tabs_[i];
+    if (tab.id == id)
+      return tab;
+  }
+  return null;
+};
+
+/**
+ * Focuses on tab with ID |id|.
+ */
+TabSwitcherView.prototype.switchToTab = function(id) {
+  var oldTab = this.findActiveTab();
+  if (oldTab)
+    oldTab.setSelected(false);
+
+  var newTab = this.findTabById(id);
+  newTab.setSelected(true);
+};
+
+TabSwitcherView.prototype.getAllTabIds = function() {
+  var ids = [];
+  for (var i = 0; i < this.tabs_.length; ++i)
+    ids.push(this.tabs_[i].id);

[arv (Not doing code reviews), 2010/11/24 19:07:38]

map

+  return ids;
+};
+
+//-----------------------------------------------------------------------------
+
+/**
+ * @constructor
+ */
+function TabEntry(id, contentView) {
+  this.id = id;
+  this.contentView = contentView;
+}
+
+TabEntry.prototype.setSelected = function(isSelected) {
+  this.active = isSelected;
+  changeClassName(this.getTabHandleNode(), 'selected', isSelected);
+  this.contentView.show(isSelected);
+};
+
+/**
+ * Returns the DOM node that is used to select the tab.
+ */
+TabEntry.prototype.getTabHandleNode = function() {
+  return document.getElementById(this.id);
+};
+