Move cc::DisplayItemList and related classes into cc/paint/

cc/debug/picture_debug_util.h

 // Copyright 2015 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.
 
 #ifndef CC_DEBUG_PICTURE_DEBUG_UTIL_H_
 #define CC_DEBUG_PICTURE_DEBUG_UTIL_H_
 
 #include <string>
 
+#include "cc/debug/debug_export.h"
+
 class SkPicture;
 
 namespace cc {
 
-class PictureDebugUtil {
+class CC_DEBUG_EXPORT PictureDebugUtil {
  public:
   static void SerializeAsBase64(const SkPicture* picture, std::string* output);
 };
 
 }  // namespace cc
 
 #endif  // CC_DEBUG_PICTURE_DEBUG_UTIL_H_