Stop doing unnecessary UTF-8 to UTF-16 conversions in JSONWriter.

base/metrics/statistics_recorder.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 "base/metrics/statistics_recorder.h"
 
 #include "base/at_exit.h"
 #include "base/debug/leak_annotations.h"
 #include "base/json/string_escape.h"
 #include "base/logging.h"
@@ skipping 154 matching lines @@
 }
 
 // static
 std::string StatisticsRecorder::ToJSON(const std::string& query) {
   if (!IsActive())
     return std::string();
 
   std::string output("{");
   if (!query.empty()) {
     output += "\"query\":";
-    JsonDoubleQuote(query, true, &output);
+    EscapeJSONString(query, true, &output);
     output += ",";
   }
 
   Histograms snapshot;
   GetSnapshot(query, &snapshot);
   output += "\"histograms\":[";
   bool first_histogram = true;
   for (Histograms::const_iterator it = snapshot.begin(); it != snapshot.end();
        ++it) {
     if (first_histogram)
@@ skipping 129 matching lines @@
 
 
 // static
 StatisticsRecorder::HistogramMap* StatisticsRecorder::histograms_ = NULL;
 // static
 StatisticsRecorder::RangesMap* StatisticsRecorder::ranges_ = NULL;
 // static
 base::Lock* StatisticsRecorder::lock_ = NULL;
 
 }  // namespace base