Pass result of blockage across content API when new tab blocked.

chrome/browser/ui/gtk/tabs/dragged_tab_controller_gtk.cc

 // 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/ui/gtk/tabs/dragged_tab_controller_gtk.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 174 matching lines @@
   }
   return NULL;
 }
 
 void DraggedTabControllerGtk::NavigationStateChanged(const WebContents* source,
                                                      unsigned changed_flags) {
   if (dragged_view_.get())
     dragged_view_->Update();
 }
 
-void DraggedTabControllerGtk::AddNewContents(WebContents* source,
+bool DraggedTabControllerGtk::AddNewContents(WebContents* source,
                                              WebContents* new_contents,
                                              WindowOpenDisposition disposition,
                                              const gfx::Rect& initial_pos,
                                              bool user_gesture) {
   DCHECK(disposition != CURRENT_TAB);
 
   // Theoretically could be called while dragging if the page tries to
   // spawn a window. Route this message back to the browser in most cases.
   if (drag_data_->GetSourceTabData()->original_delegate_) {
-    drag_data_->GetSourceTabData()->original_delegate_->AddNewContents(
+    return drag_data_->GetSourceTabData()->original_delegate_->AddNewContents(
         source, new_contents, disposition, initial_pos, user_gesture);
   }
+  return true;
 }
 
 void DraggedTabControllerGtk::LoadingStateChanged(WebContents* source) {
   // TODO(jhawkins): It would be nice to respond to this message by changing the
   // screen shot in the dragged tab.
   if (dragged_view_.get())
     dragged_view_->Update();
 }
 
 content::JavaScriptDialogCreator*
@@ skipping 666 matching lines @@
 
 bool DraggedTabControllerGtk::AreTabsConsecutive() {
   for (size_t i = 1; i < drag_data_->size(); ++i) {
     if (drag_data_->get(i - 1)->source_model_index_ + 1 !=
         drag_data_->get(i)->source_model_index_) {
       return false;
     }
   }
   return true;
 }