Revert 150969 - Disable getting histogram data from child processes other than the renderer process…

content/browser/histogram_controller.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 "content/browser/histogram_controller.h"
 
 #include "base/bind.h"
 #include "base/metrics/histogram.h"
 #include "content/browser/histogram_subscriber.h"
 #include "content/common/child_process_messages.h"
@@ skipping 52 matching lines @@
     const HistogramSubscriber* subscriber) {
   DCHECK_EQ(subscriber_, subscriber);
   subscriber_ = NULL;
 }
 
 void HistogramController::GetHistogramDataFromChildProcesses(
     int sequence_number) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   int pending_processes = 0;
-  /* TODO(rtenneti): Enable collecting histogram from child processes.
   for (BrowserChildProcessHostIterator iter; !iter.Done(); ++iter) {
     ++pending_processes;
     if (!iter.Send(new ChildProcessMsg_GetChildHistogramData(sequence_number)))
       --pending_processes;
   }
-  */
 
   BrowserThread::PostTask(
       BrowserThread::UI,
       FROM_HERE,
       base::Bind(
           &HistogramController::OnPendingProcesses,
           base::Unretained(this),
           sequence_number,
           pending_processes,
           true));
@@ skipping 15 matching lines @@
 
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
       base::Bind(&HistogramController::GetHistogramDataFromChildProcesses,
                  base::Unretained(this),
                  sequence_number));
 }
 
 }  // namespace content