tools/gn: rename char_offset to column_number

tools/gn/parse_tree_unittest.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 "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/input_file.h"
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/scope.h"
 #include "tools/gn/test_with_scope.h"
 
@@ skipping 72 matching lines @@
       "}");
   EXPECT_FALSE(input_unused.has_error());
 
   input_unused.parsed()->Execute(setup.scope(), &err);
   EXPECT_TRUE(err.has_error());
 
   // Also verify that the unused variable has the correct origin set. The
   // origin will point to the value assigned to the variable (in this case, the
   // "13" assigned to "b".
   EXPECT_EQ(3, err.location().line_number());
-  EXPECT_EQ(7, err.location().char_offset());
+  EXPECT_EQ(7, err.location().column_number());
 }
 
 TEST(ParseTree, OriginForDereference) {
   TestWithScope setup;
   TestParseInput input(
       "a = 6\n"
       "get_target_outputs(a)");
   EXPECT_FALSE(input.has_error());
 
   Err err;
   input.parsed()->Execute(setup.scope(), &err);
   EXPECT_TRUE(err.has_error());
 
   // The origin for the "not a string" error message should be where the value
   // was dereferenced (the "a" on the second line).
   EXPECT_EQ(2, err.location().line_number());
-  EXPECT_EQ(20, err.location().char_offset());
+  EXPECT_EQ(20, err.location().column_number());
 }
 
 TEST(ParseTree, SortRangeExtraction) {
   TestWithScope setup;
 
   // Ranges are [begin, end).
 
   {
     TestParseInput input(
         "sources = [\n"
@@ skipping 120 matching lines @@
   for (auto s : kBad) {
     TestParseInput input(std::string("x = ") + s);
     EXPECT_FALSE(input.has_error());
 
     TestWithScope setup;
     Err err;
     input.parsed()->Execute(setup.scope(), &err);
     EXPECT_TRUE(err.has_error());
   }
 }