tools/gn: rename char_offset to column_number

tools/gn: rename char_offset to column_number

While looking at Location and trying to understand what char offset meant,
I got very confused, because in some languages, like Portuguese, it is
hard to translate offset and thus understand what it means. Actually
char offset is referring to the column number in text buffer, which is much
easier to understand and its meaning is instantly understood, since everyone is
familiar with the concenpt of rows (lines) and columns in a text editor.

BUG=None
TEST=gn gen + gn_unittests
R=brettw@chromium.org

Committed: https://crrev.com/21aff0d0e90b1fc419971485150f76c4d2458e13
Cr-Commit-Position: refs/heads/master@{#367883}

[brettw, 2016-01-06 19:06:04]

lgtm

[tfarina, 2016-01-06 19:22:05]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2016-01-06 19:23:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1525183002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1525183002/20001

[commit-bot: I haz the power, 2016-01-06 19:50:15]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-01-06 19:51:48]

Description was changed from

==========
tools/gn: rename char_offset to column_number

While looking at Location and trying to understand what char offset meant,
I got very confused, because in some languages, like Portuguese, it is
hard to translate offset and thus understand what it means. Actually
char offset is referring to the column number in text buffer, which is much
easier to understand and its meaning is instantly understood, since everyone is
familiar with the concenpt of rows (lines) and columns in a text editor.

BUG=None
TEST=gn gen + gn_unittests
R=brettw@chromium.org
==========

to

==========
tools/gn: rename char_offset to column_number

While looking at Location and trying to understand what char offset meant,
I got very confused, because in some languages, like Portuguese, it is
hard to translate offset and thus understand what it means. Actually
char offset is referring to the column number in text buffer, which is much
easier to understand and its meaning is instantly understood, since everyone is
familiar with the concenpt of rows (lines) and columns in a text editor.

BUG=None
TEST=gn gen + gn_unittests
R=brettw@chromium.org

Committed: https://crrev.com/21aff0d0e90b1fc419971485150f76c4d2458e13
Cr-Commit-Position: refs/heads/master@{#367883}
==========

[commit-bot: I haz the power, 2016-01-06 19:51:49]

Patchset 2 (id:??) landed as
https://crrev.com/21aff0d0e90b1fc419971485150f76c4d2458e13
Cr-Commit-Position: refs/heads/master@{#367883}