Query the current window with chrome.tabs.query using -1.

chrome/renderer/resources/extensions/schema_generated_bindings.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.
 
 // 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 GetChromeHidden();
@@ skipping 896 matching lines @@
           request.callback(fs);
         request.callback = null;
       });
 
     apiFunctions.setHandleRequest("chromePrivate.decodeJPEG",
       function(jpeg_image) {
         return DecodeJPEG(jpeg_image);
       });
 
     apiFunctions.setHandleRequest("extension.getViews", function(properties) {
-      var windowId = -1;
+      var windowId = chrome.windows.WINDOW_ID_NONE;
       var type = "ALL";
       if (typeof(properties) != "undefined") {
         if (typeof(properties.type) != "undefined") {
           type = properties.type;
         }
         if (typeof(properties.windowId) != "undefined") {
           windowId = properties.windowId;
         }
       }
       return GetExtensionViews(windowId, type) || null;
     });
 
     apiFunctions.setHandleRequest("extension.getBackgroundPage", function() {
       return GetExtensionViews(-1, "BACKGROUND")[0] || null;
     });
 
     apiFunctions.setHandleRequest("extension.getExtensionTabs",
         function(windowId) {
       if (typeof(windowId) == "undefined")
-        windowId = -1;
+        windowId = chrome.windows.WINDOW_ID_NONE;
       return GetExtensionViews(windowId, "TAB");
     });
 
     apiFunctions.setHandleRequest("devtools.getTabEvents", function(tabId) {
       var tabIdProxy = {};
       var functions = ["onPageEvent", "onTabClose"];
       functions.forEach(function(name) {
         // Event disambiguation is handled by name munging.  See
         // chrome/browser/extensions/extension_devtools_events.h for the C++
         // equivalent of this logic.
@@ skipping 288 matching lines @@
     if (apiExists("pageActions"))
       setupPageActionEvents(extensionId);
     if (apiExists("experimental.socket"))
       setupSocketEvents();
     if (apiExists("ttsEngine"))
       setupTtsEngineEvents();
     if (apiExists("tts"))
       setupTtsEvents();
   });
 })();