favor DCHECK_CURRENTLY_ON for better logs in components/ (part 2)

components/storage_monitor/mtab_watcher_linux.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.
 
 // MtabWatcherLinux implementation.
 
 #include "components/storage_monitor/mtab_watcher_linux.h"
 
 #include <mntent.h>
 #include <stdio.h>
@@ skipping 20 matching lines @@
 
 }  // namespace
 
 namespace storage_monitor {
 
 MtabWatcherLinux::MtabWatcherLinux(const base::FilePath& mtab_path,
                                    base::WeakPtr<Delegate> delegate)
     : mtab_path_(mtab_path),
       delegate_(delegate),
       weak_ptr_factory_(this) {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
+  DCHECK_CURRENTLY_ON(content::BrowserThread::FILE);
   bool ret = file_watcher_.Watch(
       mtab_path_, false,
       base::Bind(&MtabWatcherLinux::OnFilePathChanged,
                  weak_ptr_factory_.GetWeakPtr()));
   if (!ret) {
     LOG(ERROR) << "Adding watch for " << mtab_path_.value() << " failed";
     return;
   }
 
   ReadMtab();
 }
 
 MtabWatcherLinux::~MtabWatcherLinux() {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
+  DCHECK_CURRENTLY_ON(content::BrowserThread::FILE);
 }
 
 void MtabWatcherLinux::ReadMtab() const {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
+  DCHECK_CURRENTLY_ON(content::BrowserThread::FILE);
 
   FILE* fp = setmntent(mtab_path_.value().c_str(), "r");
   if (!fp)
     return;
 
   MountPointDeviceMap device_map;
   mntent entry;
   char buf[512];
 
   // We return the same device mounted to multiple locations, but hide
@@ skipping 10 matching lines @@
   }
   endmntent(fp);
 
   content::BrowserThread::PostTask(
       content::BrowserThread::UI, FROM_HERE,
       base::Bind(&Delegate::UpdateMtab, delegate_, device_map));
 }
 
 void MtabWatcherLinux::OnFilePathChanged(
     const base::FilePath& path, bool error) {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::FILE));
+  DCHECK_CURRENTLY_ON(content::BrowserThread::FILE);
 
   if (path != mtab_path_) {
     // This cannot happen unless FilePathWatcher is buggy. Just ignore this
     // notification and do nothing.
     NOTREACHED();
     return;
   }
   if (error) {
     LOG(ERROR) << "Error watching " << mtab_path_.value();
     return;
   }
 
   ReadMtab();
 }
 
 }  // namespace storage_monitor