Connect SparseHistogram with the rest of stats system

content/renderer/dom_automation_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/renderer/dom_automation_controller.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/json/json_string_value_serializer.h"
 #include "base/metrics/histogram.h"
@@ skipping 165 matching lines @@
   automation_id_ = args[0].ToInt32();
   result->Set(true);
 }
 
 void DomAutomationController::GetHistogram(const CppArgumentList& args,
                                            CppVariant* result) {
   if (args.size() != 1) {
     result->SetNull();
     return;
   }
-  base::Histogram* histogram =
+  base::HistogramBase* histogram =
       base::StatisticsRecorder::FindHistogram(args[0].ToString());
   std::string output;
   if (!histogram) {
     output = "{}";
   } else {
     histogram->WriteJSON(&output);
   }
   result->Set(output);
 }
 
@@ skipping 10 matching lines @@
     return;
   }
 
   std::string histogram_json;
   sender_->Send(new ChildProcessHostMsg_GetBrowserHistogram(
       args[0].ToString(), &histogram_json));
   result->Set(histogram_json);
 }
 
 }  // namespace content