Remove legacy StartsWithASCII function.

tools/gn/input_conversion.cc

 // Copyright (c) 2013 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 "tools/gn/input_conversion.h"
 
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "tools/gn/build_settings.h"
 #include "tools/gn/err.h"
@@ skipping 98 matching lines @@
 Value DoConvertInputToValue(const Settings* settings,
                             const std::string& input,
                             const ParseNode* origin,
                             const Value& original_input_conversion,
                             const std::string& input_conversion,
                             Err* err) {
   if (input_conversion.empty())
     return Value();  // Empty string means discard the result.
 
   const char kTrimPrefix[] = "trim ";
-  if (base::StartsWithASCII(input_conversion, kTrimPrefix, true)) {
+  if (base::StartsWith(input_conversion, kTrimPrefix,
+                       base::CompareCase::SENSITIVE)) {
     std::string trimmed;
     base::TrimWhitespaceASCII(input, base::TRIM_ALL, &trimmed);
 
     // Remove "trim" prefix from the input conversion and re-run.
     return DoConvertInputToValue(
         settings, trimmed, origin, original_input_conversion,
         input_conversion.substr(arraysize(kTrimPrefix) - 1), err);
   }
 
   if (input_conversion == "value")
@@ skipping 70 matching lines @@
                           const ParseNode* origin,
                           const Value& input_conversion_value,
                           Err* err) {
   if (input_conversion_value.type() == Value::NONE)
     return Value();  // Allow null inputs to mean discard the result.
   if (!input_conversion_value.VerifyTypeIs(Value::STRING, err))
     return Value();
   return DoConvertInputToValue(settings, input, origin, input_conversion_value,
                                input_conversion_value.string_value(), err);
 }