Fix a syntax error which resulted in update.sh always using the old Clang.

Fix a syntax error which resulted in update.sh always using the old Clang.
Renamed  --is-asan-mac-builder to --is-asan-mac-builder-hackfix per Nico's suggestion.
Added more comments.

BUG=170629, 174873
TBR=thakis
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=182175

[Alexander Potapenko, 2013-02-13 09:35:38]

Nico, TBR

[hans, 2013-02-13 09:38:13]

https://codereview.chromium.org/12255003/diff/1/tools/clang/scripts/update.sh
File tools/clang/scripts/update.sh (right):

https://codereview.chromium.org/12255003/diff/1/tools/clang/scripts/update.sh...
tools/clang/scripts/update.sh:110: if [[ -n ${is_asan_mac_builder_hackfix} ]] ||
on_asan_mac_host; then
the other "-n checks" have quotation marks around the variable.. should we use
that here too?

i.e..

[[ -n "${is_asan_mac_builder_hackfix}" ]]

[Alexander Potapenko, 2013-02-13 09:42:04]

On 2013/02/13 09:38:13, hans wrote:
> https://codereview.chromium.org/12255003/diff/1/tools/clang/scripts/update.sh
> File tools/clang/scripts/update.sh (right):
> 
>
https://codereview.chromium.org/12255003/diff/1/tools/clang/scripts/update.sh...
> tools/clang/scripts/update.sh:110: if [[ -n ${is_asan_mac_builder_hackfix} ]]
||
> on_asan_mac_host; then
> the other "-n checks" have quotation marks around the variable.. should we use
> that here too?
> 
> i.e..
> 
> [[ -n "${is_asan_mac_builder_hackfix}" ]]

BASH, Y U SO COMPLICATED?

PTAL

[Alexander Potapenko, 2013-02-13 09:42:51]

It works without the quotes as well, but let it be so at least for consistency.

[hans, 2013-02-13 09:43:08]

lgtm

[Alexander Potapenko, 2013-02-13 09:45:06]

Rebased and committed.

[Nico, 2013-02-13 16:15:54]

lgtm, thanks!