Update from https://crrev.com/306655

net/http/http_cache_transaction.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 "net/http/http_cache_transaction.h"
 
 #include "build/build_config.h"
 
 #if defined(OS_POSIX)
 #include <unistd.h>
@@ skipping 2865 matching lines @@
         transaction_pattern_ == PATTERN_ENTRY_CANT_CONDITIONALIZE)) ||
       (!did_send_request && transaction_pattern_ == PATTERN_ENTRY_USED));
 
   if (!did_send_request) {
     DCHECK(transaction_pattern_ == PATTERN_ENTRY_USED);
     UMA_HISTOGRAM_TIMES("HttpCache.AccessToDone.Used", total_time);
     return;
   }
 
   TimeDelta before_send_time = send_request_since_ - first_cache_access_since_;
-  int before_send_percent =
-      total_time.ToInternalValue() == 0 ? 0
-                                        : before_send_time * 100 / total_time;
-  DCHECK_LE(0, before_send_percent);
-  DCHECK_GE(100, before_send_percent);
+  int64 before_send_percent = (total_time.ToInternalValue() == 0) ?
+      0 : before_send_time * 100 / total_time;
+  DCHECK_GE(before_send_percent, 0);
+  DCHECK_LE(before_send_percent, 100);
+  base::HistogramBase::Sample before_send_sample =
+      static_cast<base::HistogramBase::Sample>(before_send_percent);
 
   UMA_HISTOGRAM_TIMES("HttpCache.AccessToDone.SentRequest", total_time);
   UMA_HISTOGRAM_TIMES("HttpCache.BeforeSend", before_send_time);
-  UMA_HISTOGRAM_PERCENTAGE("HttpCache.PercentBeforeSend", before_send_percent);
+  UMA_HISTOGRAM_PERCENTAGE("HttpCache.PercentBeforeSend", before_send_sample);
 
   // TODO(gavinp): Remove or minimize these histograms, particularly the ones
   // below this comment after we have received initial data.
   switch (transaction_pattern_) {
     case PATTERN_ENTRY_CANT_CONDITIONALIZE: {
       UMA_HISTOGRAM_TIMES("HttpCache.BeforeSend.CantConditionalize",
                           before_send_time);
       UMA_HISTOGRAM_PERCENTAGE("HttpCache.PercentBeforeSend.CantConditionalize",
-                               before_send_percent);
+                               before_send_sample);
       break;
     }
     case PATTERN_ENTRY_NOT_CACHED: {
       UMA_HISTOGRAM_TIMES("HttpCache.BeforeSend.NotCached", before_send_time);
       UMA_HISTOGRAM_PERCENTAGE("HttpCache.PercentBeforeSend.NotCached",
-                               before_send_percent);
+                               before_send_sample);
       break;
     }
     case PATTERN_ENTRY_VALIDATED: {
       UMA_HISTOGRAM_TIMES("HttpCache.BeforeSend.Validated", before_send_time);
       UMA_HISTOGRAM_PERCENTAGE("HttpCache.PercentBeforeSend.Validated",
-                               before_send_percent);
+                               before_send_sample);
       break;
     }
     case PATTERN_ENTRY_UPDATED: {
       UMA_HISTOGRAM_TIMES("HttpCache.BeforeSend.Updated", before_send_time);
       UMA_HISTOGRAM_PERCENTAGE("HttpCache.PercentBeforeSend.Updated",
-                               before_send_percent);
+                               before_send_sample);
       break;
     }
     default:
       NOTREACHED();
   }
 }
 
 void HttpCache::Transaction::OnIOComplete(int result) {
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION("422516 Transaction::OnIOComplete"));
 
   DoLoop(result);
 }
 
 }  // namespace net