Functionality has been requested in the Extension API for Javascript to...

chrome/renderer/resources/extension_process_bindings.js

 // Copyright (c) 2009 The chrome Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // -----------------------------------------------------------------------------
 // NOTE: If you change this file you need to touch renderer_resources.grd to
 // have your change take effect.
 // -----------------------------------------------------------------------------
 
 // This script contains privileged chrome extension related javascript APIs.
 // It is loaded by pages whose URL has the chrome-extension protocol.
 
 var chrome = chrome || {};
 (function() {
   native function GetViews();
   native function GetWindow();
   native function GetCurrentWindow();
   native function GetLastFocusedWindow();
   native function CreateWindow();
   native function UpdateWindow();
   native function RemoveWindow();
   native function GetAllWindows();
   native function GetTab();
   native function GetSelectedTab();
   native function GetAllTabsInWindow();
   native function CreateTab();
   native function UpdateTab();
   native function MoveTab();
   native function RemoveTab();
+  native function GetVisibleTabCapture();
   native function GetTabLanguage();
   native function EnablePageAction();
   native function DisablePageAction();
   native function GetCurrentPageActions();
   native function GetBookmarks();
   native function GetBookmarkChildren();
   native function GetBookmarkTree();
   native function SearchBookmarks();
   native function RemoveBookmark();
   native function CreateBookmark();
@@ skipping 271 matching lines @@
   chrome.tabs.remove = function(tabId, callback) {
     validate(arguments, arguments.callee.params);
     sendRequest(RemoveTab, tabId, callback);
   };
 
   chrome.tabs.remove.params = [
     chrome.types.pInt,
     chrome.types.optFun
   ];
 
+  chrome.tabs.getVisibleTabCapture = function(windowId, callback) {

[Aaron Boodman, 2009/07/30 18:15:12]

Shouldn't this be in api.json now?

[Aaron Boodman, 2009/07/30 18:15:12]

Can we change the name to captureVisibleTab()?

+    validate(arguments, arguments.callee.params);
+    sendRequest(GetVisibleTabCapture, windowId, callback);
+  };
+
+  chrome.tabs.getVisibleTabCapture.params = [
+    chrome.types.optPInt,
+    chrome.types.fun
+  ];
+
   chrome.tabs.getLanguage = function(tabId, callback) {
     validate(arguments, arguments.callee.params);
     sendRequest(GetTabLanguage, tabId, callback);
   };
 
   chrome.tabs.getLanguage.params = [
     chrome.types.optPInt,
     chrome.types.optFun
   ];
 
@@ skipping 226 matching lines @@
     // http://code.google.com/p/chromium/issues/detail?id=16356
     chrome.self.onConnect = new chrome.Event("channel-connect:" + extensionId);
 
     setupPageActionEvents(extensionId);
   });
 
   chrome.self.getViews = function() {
     return GetViews();
   }
 })();