Cache the ranges_ vector and share the ranges_ vector

chrome/browser/browser_about_handler.cc

 // Copyright (c) 2011 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 "chrome/browser/browser_about_handler.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 831 matching lines @@
     it.Advance();
   }
 
   return data;
 }
 #endif
 
 std::string AboutHistograms(const std::string& query) {
   TimeDelta wait_time = TimeDelta::FromMilliseconds(10000);
 
+#ifndef NDEBUG
+  base::StatisticsRecorder::CollectHistogramStats("Browser");
+#endif
+
   HistogramSynchronizer* current_synchronizer =
       HistogramSynchronizer::CurrentSynchronizer();
   DCHECK(current_synchronizer != NULL);
   current_synchronizer->FetchRendererHistogramsSynchronously(wait_time);
 
   std::string unescaped_query;
   std::string unescaped_title("About Histograms");
   if (!query.empty()) {
     unescaped_query = net::UnescapeURLComponent(query, UnescapeRule::NORMAL);
     unescaped_title += " - " + unescaped_query;
@@ skipping 770 matching lines @@
   return false;
 }
 
 std::vector<std::string> ChromePaths() {
   std::vector<std::string> paths;
   paths.reserve(arraysize(kChromePaths));
   for (size_t i = 0; i < arraysize(kChromePaths); i++)
     paths.push_back(kChromePaths[i]);
   return paths;
 }