Change most uses of Pickle to base::Pickle

ipc/mojo/ipc_mojo_message_helper.cc

 // Copyright (c) 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.
 
 #include "ipc/mojo/ipc_mojo_message_helper.h"
 
 #include "ipc/mojo/ipc_mojo_handle_attachment.h"
 
 namespace IPC {
 
 // static
 bool MojoMessageHelper::WriteMessagePipeTo(
     Message* message,
     mojo::ScopedMessagePipeHandle handle) {
   message->WriteAttachment(new internal::MojoHandleAttachment(
       mojo::ScopedHandle::From(handle.Pass())));
   return true;
 }
 
 // static
 bool MojoMessageHelper::ReadMessagePipeFrom(
     const Message* message,
-    PickleIterator* iter,
+    base::PickleIterator* iter,
     mojo::ScopedMessagePipeHandle* handle) {
   scoped_refptr<MessageAttachment> attachment;
   if (!message->ReadAttachment(iter, &attachment)) {
     LOG(ERROR) << "Failed to read attachment for message pipe.";
     return false;
   }
 
   if (attachment->GetType() != MessageAttachment::TYPE_MOJO_HANDLE) {
     LOG(ERROR) << "Unxpected attachment type:" << attachment->GetType();
     return false;
   }
 
   handle->reset(mojo::MessagePipeHandle(
       static_cast<internal::MojoHandleAttachment*>(attachment.get())
           ->TakeHandle()
           .release()
           .value()));
   return true;
 }
 
 MojoMessageHelper::MojoMessageHelper() {
 }
 
 }  // namespace IPC