Remove remaining legacy SplitString calls.

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 69 matching lines @@
   // we made, rather than the result of running the block (which will be empty).
   if (what == PARSE_SCOPE) {
     DCHECK(result.type() == Value::NONE);
     result = Value(origin, scope.Pass());
   }
   return result;
 }
 
 Value ParseList(const std::string& input, const ParseNode* origin, Err* err) {
   Value ret(origin, Value::LIST);
-  std::vector<std::string> as_lines;
-  base::SplitString(input, '\n', &as_lines);
+  std::vector<std::string> as_lines = base::SplitString(
+      input, "\n", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
 
   // Trim one empty line from the end since the last line might end in a
   // newline. If the user wants more trimming, they'll specify "trim" in the
   // input conversion options.
   if (!as_lines.empty() && as_lines[as_lines.size() - 1].empty())
     as_lines.resize(as_lines.size() - 1);
 
   ret.list_value().reserve(as_lines.size());
   for (const auto& line : as_lines)
     ret.list_value().push_back(Value(origin, line));
@@ skipping 99 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);
 }