WebUI TaskManager: Add "Activate page" feature.

chrome/browser/resources/task_manager/main.js

Index: chrome/browser/resources/task_manager/main.js
diff --git a/chrome/browser/resources/task_manager/main.js b/chrome/browser/resources/task_manager/main.js
index 49eb3b2bb3890014fb322c3e94ba741a4ef78a40..d2089b31e2695aa7a2a42ca921748db06dfda0b9 100644
--- a/chrome/browser/resources/task_manager/main.js
+++ b/chrome/browser/resources/task_manager/main.js
@@ -29,6 +29,9 @@ var DEFAULT_COLUMNS = [
     ['v8MemoryAllocatedSize', 'JAVASCRIPT_MEMORY_ALLOCATED_COLUMN', 120, false],
 ];
 
+var COMMAND_CONTEXTMENU_COLUMN_PREFIX = 'columnContextMenu';
+var COMMAND_CONTEXTMENU_TABLE_PREFIX = 'tableContextMenu';
+
 var localStrings = new LocalStrings();
 
 TaskManager.prototype = {
@@ -123,6 +126,14 @@ TaskManager.prototype = {
   },
 
   /**
+   * Sends command to activate a page.
+   * @public
+   */
+  activatePage: function (uniqueId) {
+    chrome.send('activatePage', [uniqueId]);
+  },
+
+  /**
    * Initializes taskmanager.
    * @public
    */
@@ -233,7 +244,7 @@ TaskManager.prototype = {
 
       // Creates command element to receive event.
       var command = this.document_.createElement('command');
-      command.id = 'columnContextMenu-' + column[0];
+      command.id = COMMAND_CONTEXTMENU_COLUMN_PREFIX + '-' + column[0];
       cr.ui.Command.decorate(command);
       this.column_menu_commands_[command.id] = command;
       this.commandsElement_.appendChild(command);
@@ -264,20 +275,25 @@ TaskManager.prototype = {
     this.table_menu_commands_ = [];
     this.tableContextMenu_ = this.document_.createElement('menu');
 
-    // Creates command element to receive event.
-    var command = this.document_.createElement('command');
-    command.id = 'tableContextMenu-inspect';
-    cr.ui.Command.decorate(command);
-    this.table_menu_commands_[command.id] = command;
-    this.commandsElement_.appendChild(command);
-
-    // Creates menuitem element.
-    var item = this.document_.createElement('menuitem');
-    item.command = command;
-    command.menuitem = item;
-    var localized_label = localStrings.getString('INSPECT');
-    item.textContent = (localized_label != "") ? localized_label : "Inspect";
-    this.tableContextMenu_.appendChild(item);
+    var addMenuItem = function (tm, command_id, string_id, default_label) {
+      // Creates command element to receive event.
+      var command = tm.document_.createElement('command');
+      command.id = COMMAND_CONTEXTMENU_TABLE_PREFIX + '-' + command_id;
+      cr.ui.Command.decorate(command);
+      tm.table_menu_commands_[command.id] = command;
+      tm.commandsElement_.appendChild(command);
+
+      // Creates menuitem element.
+      var item = tm.document_.createElement('menuitem');
+      item.command = command;
+      command.menuitem = item;
+      var localized_label = localStrings.getString(string_id);
+      item.textContent = localized_label || default_label;
+      tm.tableContextMenu_.appendChild(item);
+    };
+
+    addMenuItem(this, 'inspect', 'INSPECT', "Inspect");
+    addMenuItem(this, 'activate', 'ACTIVATE', "Activate");
 
     this.document_.body.appendChild(this.tableContextMenu_);
     cr.ui.Menu.decorate(this.tableContextMenu_);
@@ -350,6 +366,10 @@ TaskManager.prototype = {
           cr.ui.contextMenuHandler.addContextMenuProperty(label);
           label.contextMenu = this.tableContextMenu_;
 
+          label.addEventListener('dblclick', (function(uniqueId) {
+              this.activatePage(uniqueId);
+          }).bind(this, entry['uniqueId'][i]));
+
           label.data = entry;
           label.index_in_group = i;
         } else {
@@ -404,15 +424,25 @@ TaskManager.prototype = {
    */
   onCommand_: function(event) {
     var command = event.command;
-    if (command.id.substr(0, 18) == 'columnContextMenu-') {
-      console.log(command.id.substr(18));
-      this.onColumnContextMenu_(command.id.substr(18), command);
-    } else if (command.id == 'tableContextMenu-inspect') {
-      var contextMenuTarget = this.currentContextMenuTarget_;
-      if (contextMenuTarget) {
-        this.inspect(contextMenuTarget);
-        this.currentContextMenuTarget_ = undefined;
-      }
+    var command_id = command.id.split('-', 2);
+
+    var main_command = command_id[0];
+    var sub_command = command_id[1];
+
+    if (main_command == COMMAND_CONTEXTMENU_COLUMN_PREFIX) {
+      this.onColumnContextMenu_(sub_command, command);
+    } else if (main_command == COMMAND_CONTEXTMENU_TABLE_PREFIX) {
+      var target_unique_id = this.currentContextMenuTarget_;
+
+      if (!target_unique_id)
+        return;
+
+      if (sub_command == 'inspect')
+        this.inspect(target_unique_id);
+      else if (sub_command == 'activate')
+        this.activatePage(target_unique_id);
+
+      this.currentContextMenuTarget_ = undefined;
     }
   },
 
@@ -425,12 +455,15 @@ TaskManager.prototype = {
    * will be replaced when it is refleshed.
    */
   onTableContextMenuOpened_: function (e) {
-    var command = this.table_menu_commands_['tableContextMenu-inspect'];
-    var menuItem = command.menuitem;
+    var mc = this.table_menu_commands_;
+    var inspect_menuitem =
+        mc[COMMAND_CONTEXTMENU_TABLE_PREFIX + '-inspect'].menuitem;
+    var activate_menuitem =
+        mc[COMMAND_CONTEXTMENU_TABLE_PREFIX + '-activate'].menuitem;
 
     // Disabled by default.
-    menuItem.disabled = true;
-    this.currentContextMenuTarget_ = undefined;
+    inspect_menuitem.disabled = true;
+    activate_menuitem.disabled = true;
 
     var target = e.target;
     var classes = target.classList;
@@ -445,12 +478,16 @@ TaskManager.prototype = {
 
     var index_in_group = target.index_in_group;
 
-    var canInspect = target.data['canInspect'][index_in_group];
-    if (canInspect) {
-      menuItem.disabled = false;
-      this.currentContextMenuTarget_ =
-          target.data['uniqueId'][index_in_group];
-    }
+    // Sets the uniqueId for current target page under the mouse corsor.
+    this.currentContextMenuTarget_ = target.data['uniqueId'][index_in_group];
+
+    // Enables if the page can be inspected.
+    if (target.data['canInspect'][index_in_group])
+      inspect_menuitem.disabled = false;
+
+    // Enables if the page can be activated.
+    if (target.data['canActivate'][index_in_group])
+      activate_menuitem.disabled = false;
   },
 
   onColumnContextMenu_: function(id, command) {