Update base::StartsWith calls to new form

chrome/browser/about_flags.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 "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 2400 matching lines @@
 
 base::HistogramBase::Sample GetSwitchUMAId(const std::string& switch_name) {
   return static_cast<base::HistogramBase::Sample>(
       metrics::HashMetricName(switch_name));
 }
 
 void ReportCustomFlags(const std::string& uma_histogram_hame,
                        const std::set<std::string>& command_line_difference) {
   for (const std::string& flag : command_line_difference) {
     int uma_id = about_flags::testing::kBadSwitchFormatHistogramId;
-    if (base::StartsWithASCII(flag, "--", true /* case_sensitive */)) {
+    if (base::StartsWith(flag, "--", base::CompareCase::SENSITIVE)) {
       // Skip '--' before switch name.
       std::string switch_name(flag.substr(2));
 
       // Kill value, if any.
       const size_t value_pos = switch_name.find('=');
       if (value_pos != std::string::npos)
         switch_name.resize(value_pos);
 
       uma_id = GetSwitchUMAId(switch_name);
     } else {
@@ skipping 204 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags