Clear the clipboard closing Incognito window

ui/base/clipboard/clipboard_mac.mm

 // 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/base/clipboard/clipboard.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/basictypes.h"
 #include "base/file_path.h"
@@ skipping 72 matching lines @@
 }
 
 Clipboard::Clipboard() {
   DCHECK(CalledOnValidThread());
 }
 
 Clipboard::~Clipboard() {
   DCHECK(CalledOnValidThread());
 }
 
-void Clipboard::WriteObjects(Buffer buffer, const ObjectMap& objects) {
+void Clipboard::WriteObjectsImpl(Buffer buffer, const ObjectMap& objects) {
   DCHECK(CalledOnValidThread());
   DCHECK_EQ(buffer, BUFFER_STANDARD);
 
   NSPasteboard* pb = GetPasteboard();
   [pb declareTypes:[NSArray array] owner:nil];
 
   for (ObjectMap::const_iterator iter = objects.begin();
        iter != objects.end(); ++iter) {
     DispatchObject(static_cast<ObjectType>(iter->first), iter->second);
   }
@@ skipping 375 matching lines @@
   return type;
 }
 
 // static
 const Clipboard::FormatType& Clipboard::GetPepperCustomDataFormatType() {
   CR_DEFINE_STATIC_LOCAL(FormatType, type, (kPepperCustomDataPboardType));
   return type;
 }
 
 }  // namespace ui