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

chrome/browser/chromeos/login/signin/merge_session_throttle.cc

Index: chrome/browser/chromeos/login/signin/merge_session_throttle.cc
diff --git a/chrome/browser/chromeos/login/signin/merge_session_throttle.cc b/chrome/browser/chromeos/login/signin/merge_session_throttle.cc
index b4ce9d65bc5fac368d4d9dbd91ba7adcd4ee9de0..442de8325af45fb7e5b9843f7eed38129717871f 100644
--- a/chrome/browser/chromeos/login/signin/merge_session_throttle.cc
+++ b/chrome/browser/chromeos/login/signin/merge_session_throttle.cc
@@ -77,7 +77,7 @@ MergeSessionThrottle::MergeSessionThrottle(net::URLRequest* request,
 }
 
 MergeSessionThrottle::~MergeSessionThrottle() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
 }
 
 void MergeSessionThrottle::WillStartRequest(bool* defer) {
@@ -112,7 +112,7 @@ bool MergeSessionThrottle::AreAllSessionMergedAlready() {
 }
 
 void MergeSessionThrottle::OnBlockingPageComplete() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
   controller()->Resume();
 }
 
@@ -160,7 +160,7 @@ void MergeSessionThrottle::UnblockProfile(Profile* profile) {
 bool MergeSessionThrottle::ShouldDelayRequest(
     int render_process_id,
     int render_view_id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   if (!user_manager::UserManager::Get()->IsUserLoggedIn()) {
     return false;
@@ -247,7 +247,7 @@ void MergeSessionThrottle::DeleayResourceLoadingOnUIThread(
     int render_view_id,
     const GURL& url,
     const CompletionCallback& callback) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   if (ShouldDelayRequest(render_process_id, render_view_id)) {
     // There is a chance that the tab closed after we decided to show