content: Use base::MessageLoop.

content/browser/histogram_synchronizer.cc

Index: content/browser/histogram_synchronizer.cc
diff --git a/content/browser/histogram_synchronizer.cc b/content/browser/histogram_synchronizer.cc
index b2db39ba5cfe2053a068e65856edb63958b96fdc..5a1e6f9a413f17f72197dadd79d6c27de6947107 100644
--- a/content/browser/histogram_synchronizer.cc
+++ b/content/browser/histogram_synchronizer.cc
@@ -201,7 +201,7 @@ void HistogramSynchronizer::FetchHistograms() {
       base::TimeDelta::FromMinutes(1));
 }
 
-void FetchHistogramsAsynchronously(MessageLoop* callback_thread,
+void FetchHistogramsAsynchronously(base::MessageLoop* callback_thread,
                                    const base::Closure& callback,
                                    base::TimeDelta wait_time) {
   HistogramSynchronizer::FetchHistogramsAsynchronously(
@@ -210,7 +210,7 @@ void FetchHistogramsAsynchronously(MessageLoop* callback_thread,
 
 // static
 void HistogramSynchronizer::FetchHistogramsAsynchronously(
-    MessageLoop* callback_thread,
+    base::MessageLoop* callback_thread,
     const base::Closure& callback,
     base::TimeDelta wait_time) {
   DCHECK(callback_thread != NULL);
@@ -287,10 +287,10 @@ void HistogramSynchronizer::OnHistogramDataCollected(
 }
 
 void HistogramSynchronizer::SetCallbackTaskAndThread(
-    MessageLoop* callback_thread,
+    base::MessageLoop* callback_thread,
     const base::Closure& callback) {
   base::Closure old_callback;
-  MessageLoop* old_thread = NULL;
+  base::MessageLoop* old_thread = NULL;
   {
     base::AutoLock auto_lock(lock_);
     old_callback = callback_;
@@ -307,7 +307,7 @@ void HistogramSynchronizer::SetCallbackTaskAndThread(
 void HistogramSynchronizer::ForceHistogramSynchronizationDoneCallback(
     int sequence_number) {
   base::Closure callback;
-  MessageLoop* thread = NULL;
+  base::MessageLoop* thread = NULL;
   {
     base::AutoLock lock(lock_);
     if (sequence_number != async_sequence_number_)
@@ -320,7 +320,7 @@ void HistogramSynchronizer::ForceHistogramSynchronizationDoneCallback(
   InternalPostTask(thread, callback);
 }
 
-void HistogramSynchronizer::InternalPostTask(MessageLoop* thread,
+void HistogramSynchronizer::InternalPostTask(base::MessageLoop* thread,
                                              const base::Closure& callback) {
   if (callback.is_null() || !thread)
     return;