favor DCHECK_CURRENTLY_ON for better logs in chrome/browser/chromeos/

chrome/browser/chromeos/memory/low_memory_observer.cc

 // Copyright (c) 2012 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/browser/chromeos/memory/low_memory_observer.h"
 
 #include <fcntl.h>
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 99 matching lines @@
   int file_descriptor_;
   base::OneShotTimer<LowMemoryObserverImpl> timer_;
 
   DISALLOW_COPY_AND_ASSIGN(LowMemoryObserverImpl);
 };
 
 void LowMemoryObserverImpl::StartObservingOnFileThread() {
   DCHECK_LE(file_descriptor_, 0)
       << "Attempted to start observation when it was already started.";
   DCHECK(watcher_.get() == NULL);
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
   DCHECK(base::MessageLoopForIO::current());
 
   file_descriptor_ = ::open(kLowMemFile, O_RDONLY);
   // Don't report this error unless we're really running on ChromeOS
   // to avoid testing spam.
   if (file_descriptor_ < 0 && base::SysInfo::IsRunningOnChromeOS()) {
     PLOG(ERROR) << "Unable to open " << kLowMemFile;
     return;
   }
   watcher_.reset(new base::MessageLoopForIO::FileDescriptorWatcher);
   StartWatchingDescriptor();
 }
 
 void LowMemoryObserverImpl::StopObservingOnFileThread() {
   // If StartObserving failed, StopObserving will still get called.
   timer_.Stop();
   if (file_descriptor_ >= 0) {
-    DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+    DCHECK_CURRENTLY_ON(BrowserThread::FILE);
     watcher_.reset(NULL);
     ::close(file_descriptor_);
     file_descriptor_ = -1;
   }
 }
 
 void LowMemoryObserverImpl::ScheduleNextObservation() {
   timer_.Start(FROM_HERE,
                base::TimeDelta::FromMilliseconds(kLowMemoryCheckTimeoutMs),
                this,
                &LowMemoryObserverImpl::StartWatchingDescriptor);
 }
 
 void LowMemoryObserverImpl::StartWatchingDescriptor() {
   DCHECK(watcher_.get());
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+  DCHECK_CURRENTLY_ON(BrowserThread::FILE);
   DCHECK(base::MessageLoopForIO::current());
   if (file_descriptor_ < 0)
     return;
   if (!base::MessageLoopForIO::current()->WatchFileDescriptor(
           file_descriptor_,
           false,  // persistent=false: We want it to fire once and reschedule.
           base::MessageLoopForIO::WATCH_READ,
           watcher_.get(),
           &watcher_delegate_)) {
     LOG(ERROR) << "Unable to watch " << kLowMemFile;
@@ skipping 17 matching lines @@
 
 void LowMemoryObserver::Stop() {
   BrowserThread::PostTask(
       BrowserThread::FILE,
       FROM_HERE,
       base::Bind(&LowMemoryObserverImpl::StopObservingOnFileThread,
                  observer_.get()));
 }
 
 }  // namespace chromeos