Disallow display of multiple experimental.extension.popup(...) windows

chrome/renderer/extensions/extension_process_bindings.cc

 // 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.
 
 #include "chrome/renderer/extensions/extension_process_bindings.h"
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 279 matching lines @@
     if (extension_id.empty())
       return v8::Undefined();
 
     ExtensionViewAccumulator  popup_matcher(extension_id,
                                             browser_window_id,
                                             viewtype_to_find);
     RenderView::ForEach(&popup_matcher);
 
     if (0 == popup_matcher.views()->Length())
       return v8::Undefined();
-    DCHECK(popup_matcher.views()->Has(0));
+    DCHECK(1 == popup_matcher.views()->Length());
 
     // Return the first view found.
     return popup_matcher.views()->Get(v8::Integer::New(0));
   }
 
   static v8::Handle<v8::Value> GetPopupView(const v8::Arguments& args) {
     return PopupViewFinder(args, ViewType::EXTENSION_POPUP);
   }
 
   static v8::Handle<v8::Value> GetPopupParentWindow(const v8::Arguments& args) {
@@ skipping 371 matching lines @@
     return;
 
   v8::HandleScope handle_scope;
   WebFrame* frame = view->mainFrame();
   v8::Local<v8::Context> context = frame->mainWorldScriptContext();
   v8::Handle<v8::Value> argv[1];
   argv[0] = v8::String::New(type_str);
   bindings_utils::CallFunctionInContext(context, "setViewType",
                                         arraysize(argv), argv);
 }