Use a different define to decide which CRC library to use.

Use a different define to decide which CRC library to use.

Change 8569018 used a #ifdef to conditionally decide which external
library to use for Crc calculation. It used OS_CHROMIUMOS to tell
if the build was targetted at Chromium OS.

However, it broke Chromium OS builds of the full Chromium tree in
some cases (heapcheck bots), and was reverted.

Since I really only want to change the library when building from
inside a custom ebuild in the Chromium OS build, it makes sense
to use a #define custom to that ebuild.

So, this change is the same as 8569018, except that is uses
COURGETTE_USE_CRC_LIB instead of OS_CHROMIUMOS.

BUG=8569018
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=112565

[sra1, 2011-12-01 02:20:44]

LGTM.

[commit-bot: I haz the power, 2011-12-01 20:58:20]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dgarrett@chromium.org/8763014/1

[commit-bot: I haz the power, 2011-12-01 22:59:19]

Change committed as 112565