Make UMA_HISTOGRAM_ENUMERATION work with scoped enums.

components/history/core/browser/history_backend.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 "components/history/core/browser/history_backend.h"
 
 #include <algorithm>
 #include <functional>
 #include <list>
 #include <map>
@@ skipping 713 matching lines @@
     first_recorded_time_ = base::Time();
   }
   if (thumbnail_db_) {
     thumbnail_db_->CommitTransaction();
     thumbnail_db_.reset();
   }
 }
 
 void HistoryBackend::RecordTopHostsMetrics(const GURL& url) {
   // Convert index from 0-based to 1-based.
-  UMA_HISTOGRAM_ENUMERATION("History.TopHostsVisitsByRank",
-                            HostRankIfAvailable(url) + 1, kMaxTopHosts + 2);
+  UMA_HISTOGRAM_EXACT_LINEAR("History.TopHostsVisitsByRank",
+                             HostRankIfAvailable(url) + 1, kMaxTopHosts + 2);
 }
 
 std::pair<URLID, VisitID> HistoryBackend::AddPageVisit(
     const GURL& url,
     Time time,
     VisitID referring_visit,
     ui::PageTransition transition,
     VisitSource visit_source) {
   // Top-level frame navigations are visible, everything else is hidden
   bool new_hidden = !ui::PageTransitionIsMainFrame(transition);
@@ skipping 1893 matching lines @@
   // transaction is currently open.
   db_->CommitTransaction();
   db_->Vacuum();
   db_->BeginTransaction();
   db_->GetStartDate(&first_recorded_time_);
 
   return true;
 }
 
 }  // namespace history