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

chrome/browser/extensions/extension_tabs_module.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
 #include "chrome/browser/extensions/extension_tabs_module.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/base64.h"
 #include "base/bind.h"
@@ skipping 763 matching lines @@
     std::string value;
     EXTENSION_FUNCTION_VALIDATE(query->GetString(keys::kUrlKey, &value));
     url_pattern = URLPattern(URLPattern::SCHEME_ALL, value);
   }
 
   std::string title;
   if (query->HasKey(keys::kTitleKey))
     EXTENSION_FUNCTION_VALIDATE(
         query->GetString(keys::kTitleKey, &title));
 
-  int window_id = -1;
+  int window_id = extension_misc::kUnknownWindowId;
   if (query->HasKey(keys::kWindowIdKey))
     EXTENSION_FUNCTION_VALIDATE(
         query->GetInteger(keys::kWindowIdKey, &window_id));
 
   std::string window_type;
   if (query->HasKey(keys::kWindowTypeLongKey))
     EXTENSION_FUNCTION_VALIDATE(
         query->GetString(keys::kWindowTypeLongKey, &window_type));
 
   ListValue* result = new ListValue();
   for (BrowserList::const_iterator browser = BrowserList::begin();
        browser != BrowserList::end(); ++browser) {
     if (!profile()->IsSameProfile((*browser)->profile()))
       continue;
 
     if (!(*browser)->window())
       continue;
 
     if (window_id >= 0 && window_id != ExtensionTabUtil::GetWindowId(*browser))
       continue;
 
+    if (window_id == extension_misc::kCurrentWindowId &&
+        *browser != GetCurrentBrowser())
+      continue;
+
     if (!window_type.empty() &&
         window_type != ExtensionTabUtil::GetWindowTypeText(*browser))
       continue;
 
     TabStripModel* tab_strip = (*browser)->tabstrip_model();
     for (int i = 0; i < tab_strip->count(); ++i) {
       const WebContents* web_contents =
           tab_strip->GetTabContentsAt(i)->web_contents();
 
       if (!MatchesQueryArg(selected, tab_strip->IsTabSelected(i)))
@@ skipping 845 matching lines @@
   // called for every API call the extension made.
   GotLanguage(language);
 }
 
 void DetectTabLanguageFunction::GotLanguage(const std::string& language) {
   result_.reset(Value::CreateStringValue(language.c_str()));
   SendResponse(true);
 
   Release();  // Balanced in Run()
 }