Some fixes to panel support on Windows:

chrome/browser/ui/panels/panel_manager.cc

 // Copyright (c) 2011 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/panels/panel_manager.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 338 matching lines @@
 
 void PanelManager::RemoveAll() {
   // This should not be called when we're in the process of dragging.
   DCHECK(dragging_panel_index_ == kInvalidPanelIndex);
 
   // Start from the bottom to avoid reshuffling.
   for (Panels::reverse_iterator iter = panels_.rbegin();
        iter != panels_.rend(); ++iter)
     (*iter)->Close();
 }
+
+bool PanelManager::is_dragging_panel() const {
+  return dragging_panel_index_ != kInvalidPanelIndex;
+}