Create a visible window with class name Chrome_RenderWidgetHostHWND which corresponds to the bounds…

ui/views/win/hwnd_message_handler.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 "ui/views/win/hwnd_message_handler.h"
 
 #include <dwmapi.h>
 #include <shellapi.h>
 #include <wtsapi32.h>
 #pragma comment(lib, "wtsapi32.lib")
@@ skipping 770 matching lines @@
     fwi.dwFlags = FLASHW_STOP;
   }
   FlashWindowEx(&fwi);
 }
 
 void HWNDMessageHandler::ClearNativeFocus() {
   ::SetFocus(hwnd());
 }
 
 void HWNDMessageHandler::SetCapture() {
-  DCHECK(!HasCapture());
+  // DCHECK(!HasCapture());

[scottmg, 2014/01/31 21:52:01]

when is not doing this necessary? wouldn't it either be on the legacy, or us?

[ananta, 2014/01/31 23:56:26]

The dummy Chrome_RenderWidgetHostHWND class sets capture to the parent.
When the parent receives a lbuttondown, it sets capture again which causes this
DCHECK to fire.

   ::SetCapture(hwnd());
 }
 
 void HWNDMessageHandler::ReleaseCapture() {
   if (HasCapture())
     ::ReleaseCapture();
 }
 
 bool HWNDMessageHandler::HasCapture() const {
   return ::GetCapture() == hwnd();
@@ skipping 524 matching lines @@
   return handled;
 }
 
 void HWNDMessageHandler::OnCancelMode() {
   delegate_->HandleCancelMode();
   // Need default handling, otherwise capture and other things aren't canceled.
   SetMsgHandled(FALSE);
 }
 
 void HWNDMessageHandler::OnCaptureChanged(HWND window) {
-  delegate_->HandleCaptureLost();
+  if (!HasCapture())
+    delegate_->HandleCaptureLost();
 }
 
 void HWNDMessageHandler::OnClose() {
   delegate_->HandleClose();
 }
 
 void HWNDMessageHandler::OnCommand(UINT notification_code,
                                    int command,
                                    HWND window) {
   // If the notification code is > 1 it means it is control specific and we
@@ skipping 1074 matching lines @@
   SetMsgHandled(FALSE);
 }
 
 void HWNDMessageHandler::HandleTouchEvents(const TouchEvents& touch_events) {
   base::WeakPtr<HWNDMessageHandler> ref(weak_factory_.GetWeakPtr());
   for (size_t i = 0; i < touch_events.size() && ref; ++i)
     delegate_->HandleTouchEvent(touch_events[i]);
 }
 
 }  // namespace views