add a couple of casts.

components/offline_pages/offline_page_model.cc

 // Copyright 2015 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/offline_pages/offline_page_model.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 697 matching lines @@
     UMA_HISTOGRAM_COUNTS(
         AddHistogramSuffix(
             client_id, "OfflinePages.DeletePage.AccessCount").c_str(),
         iter->second.access_count);
     FOR_EACH_OBSERVER(
         Observer, observers_,
         OfflinePageDeleted(iter->second.offline_id, iter->second.client_id));
     offline_pages_.erase(iter);
   }
   if (offline_ids.size() > 1) {
-    UMA_HISTOGRAM_COUNTS("OfflinePages.BatchDelete.Count", offline_ids.size());
+    UMA_HISTOGRAM_COUNTS("OfflinePages.BatchDelete.Count",
+                         static_cast<int32_t>(offline_ids.size()));
     UMA_HISTOGRAM_MEMORY_KB(
         "OfflinePages.BatchDelete.TotalPageSize", total_size / 1024);
   }
   // Deleting multiple pages always succeeds when it gets to this point.
   InformDeletePageDone(callback, (success || offline_ids.size() > 1)
                                      ? DeletePageResult::SUCCESS
                                      : DeletePageResult::STORE_FAILURE);
 }
 
 void OfflinePageModel::InformDeletePageDone(const DeletePageCallback& callback,
@@ skipping 97 matching lines @@
 void OfflinePageModel::RunWhenLoaded(const base::Closure& task) {
   if (!is_loaded_) {
     delayed_tasks_.push_back(task);
     return;
   }
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE, task);
 }
 
 }  // namespace offline_pages