Migrate more files to histogram_macros.h from histogram.h.

extensions/browser/content_hash_reader.cc

 // Copyright 2014 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 "extensions/browser/content_hash_reader.h"
 
 #include "base/base64.h"
 #include "base/files/file_util.h"
 #include "base/json/json_reader.h"
-#include "base/metrics/histogram.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/string_util.h"
 #include "base/timer/elapsed_timer.h"
 #include "base/values.h"
 #include "crypto/sha2.h"
 #include "extensions/browser/computed_hashes.h"
 #include "extensions/browser/content_hash_tree.h"
 #include "extensions/browser/verified_contents.h"
 #include "extensions/common/extension.h"
 #include "extensions/common/file_util.h"
 
@@ skipping 92 matching lines @@
   DCHECK(block_index >= 0);
 
   if (static_cast<unsigned>(block_index) >= hashes_.size())
     return false;
   *result = &hashes_[block_index];
 
   return true;
 }
 
 }  // namespace extensions