Properly Remove Autofill Keyboard Listener.

content/browser/renderer_host/render_widget_host_impl.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 "content/browser/renderer_host/render_widget_host_impl.h"
 
 #include <math.h>
 #include <utility>
 
 #include "base/auto_reset.h"
@@ skipping 1203 matching lines @@
     const WebKit::WebTouchEvent& touch_event) {
   touch_event_queue_->QueueEvent(touch_event);
 }
 
 void RenderWidgetHostImpl::AddKeyboardListener(KeyboardListener* listener) {
   keyboard_listeners_.push_back(listener);
 }
 
 void RenderWidgetHostImpl::RemoveKeyboardListener(
     KeyboardListener* listener) {
+  // Ensure that the element is actually in the list.
+  DCHECK(std::find(keyboard_listeners_.begin(), keyboard_listeners_.end(),
+                   listener) != keyboard_listeners_.end());
   keyboard_listeners_.remove(listener);
 }
 
 void RenderWidgetHostImpl::NotifyScreenInfoChanged() {
   WebKit::WebScreenInfo screen_info;
   GetWebScreenInfo(&screen_info);
   Send(new ViewMsg_ScreenInfoChanged(GetRoutingID(), screen_info));
 }
 
 void RenderWidgetHostImpl::UpdateVSyncParameters(base::TimeTicks timebase,
@@ skipping 1170 matching lines @@
     return;
 
   OnRenderAutoResized(new_size);
 }
 
 void RenderWidgetHostImpl::DetachDelegate() {
   delegate_ = NULL;
 }
 
 }  // namespace content