gn: attach comments to parse tree

tools/gn/c_include_iterator.cc

 // Copyright 2014 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/c_include_iterator.h"
 
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "tools/gn/input_file.h"
 #include "tools/gn/location.h"
@@ skipping 115 matching lines @@
   int cur_line_number = 0;
   while (lines_since_last_include_ <= kMaxNonIncludeLines &&
          GetNextLine(&line, &cur_line_number)) {
     base::StringPiece include_contents;
     int begin_char;
     IncludeType type = ExtractInclude(line, &include_contents, &begin_char);
     if (type == INCLUDE_USER) {
       // Only count user includes for now.
       *out = include_contents;
       *location = LocationRange(
-          Location(input_file_, cur_line_number, begin_char),
-          Location(input_file_, cur_line_number,
-                   begin_char + static_cast<int>(include_contents.size())));
+          Location(input_file_,
+                   cur_line_number,
+                   begin_char,
+                   -1 /* TODO(scottmg): Is this important? */),
+          Location(input_file_,
+                   cur_line_number,
+                   begin_char + static_cast<int>(include_contents.size()),
+                   -1 /* TODO(scottmg): Is this important? */));
 
       lines_since_last_include_ = 0;
       return true;
     }
 
     if (ShouldCountTowardNonIncludeLines(line))
       lines_since_last_include_++;
   }
   return false;
 }
 
 bool CIncludeIterator::GetNextLine(base::StringPiece* line, int* line_number) {
   if (offset_ == file_.size())
     return false;
 
   size_t begin = offset_;
   while (offset_ < file_.size() && file_[offset_] != '\n')
     offset_++;
   line_number_++;
 
   *line = file_.substr(begin, offset_ - begin);
   *line_number = line_number_;
 
   // If we didn't hit EOF, skip past the newline for the next one.
   if (offset_ < file_.size())
     offset_++;
   return true;
 }