Move Pickle to base namespace.

chrome/common/content_settings_pattern_serializer.h

 // Copyright (c) 2014 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 CHROME_COMMON_CONTENT_SETTINGS_PATTERN_SERIALIZER_H_
 #define CHROME_COMMON_CONTENT_SETTINGS_PATTERN_SERIALIZER_H_
 
 #include "base/macros.h"
 
+namespace base {
+class PickleIterator;
+}
+
 namespace IPC {
 class Message;
 }
 
 class ContentSettingsPattern;
-class PickleIterator;
 
 class ContentSettingsPatternSerializer {
  public:
   // Serializes the pattern to an IPC message.
   static void WriteToMessage(const ContentSettingsPattern& pattern,
                              IPC::Message* m);
   // Deserializes the pattern from the IPC message.
-  static bool ReadFromMessage(const IPC::Message* m, PickleIterator* iter,
+  static bool ReadFromMessage(const IPC::Message* m,
+                              base::PickleIterator* iter,
                               ContentSettingsPattern* pattern);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ContentSettingsPatternSerializer);
 };
 
 #endif  // CHROME_COMMON_CONTENT_SETTINGS_PATTERN_SERIALIZER_H_