Revert: Internalize JSON chunk merging to trace_event.h API.

content/browser/trace_controller.cc

Index: content/browser/trace_controller.cc
diff --git a/content/browser/trace_controller.cc b/content/browser/trace_controller.cc
index daff2a1e7ea46172a2f744c9f82da8cf82f0ad0e..4464a8b5881db90a42fb24f2795ae84dafb1fd4a 100644
--- a/content/browser/trace_controller.cc
+++ b/content/browser/trace_controller.cc
@@ -224,19 +224,19 @@ void TraceController::OnEndTracingAck(
 
 void TraceController::OnTraceDataCollected(
     const scoped_refptr<base::debug::TraceLog::RefCountedString>&
-        events_str_ptr) {
+        json_events_str_ptr) {
   // OnTraceDataCollected may be called from any browser thread, either by the
   // local event trace system or from child processes via TraceMessageFilter.
   if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
     BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
         base::Bind(&TraceController::OnTraceDataCollected,
-                   base::Unretained(this), events_str_ptr));
+                   base::Unretained(this), json_events_str_ptr));
     return;
   }
 
   // Drop trace events if we are just getting categories.
   if (subscriber_ && !is_get_categories_)
-    subscriber_->OnTraceDataCollected(events_str_ptr->data);
+    subscriber_->OnTraceDataCollected(json_events_str_ptr->data);
 }
 
 void TraceController::OnTraceBufferFull() {