Remove implicit conversions from scoped_refptr to T* in chrome/

chrome/utility/image_writer/disk_unmounter_mac.cc

 // Copyright 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.
 
 #include "chrome/utility/image_writer/disk_unmounter_mac.h"
 
 #include <sys/socket.h>
 #include <IOKit/storage/IOStorageProtocolCharacteristics.h>
 
 #include "base/message_loop/message_loop_proxy.h"
@@ skipping 13 matching lines @@
 
 DiskUnmounterMac::~DiskUnmounterMac() {
   if (disk_)
     DADiskUnclaim(disk_);
 }
 
 void DiskUnmounterMac::Unmount(const std::string& device_path,
                                const base::Closure& success_continuation,
                                const base::Closure& failure_continuation) {
   // Should only be used once.
-  DCHECK(!original_thread_);
+  DCHECK(!original_thread_.get());
   original_thread_ = base::MessageLoopProxy::current();
   success_continuation_ = success_continuation;
   failure_continuation_ = failure_continuation;
 
   cf_thread_.message_loop()->PostTask(
       FROM_HERE,
       base::Bind(&DiskUnmounterMac::UnmountOnWorker,
                  base::Unretained(this),
                  device_path));
 }
@@ skipping 71 matching lines @@
               this,
               DiskClaimed,
               this);
 }
 
 void DiskUnmounterMac::Error() {
   original_thread_->PostTask(FROM_HERE, failure_continuation_);
 }
 
 }  // namespace image_writer