Use system constants instead of NULL for unset PID.

Use system constants instead of NULL for unset PID.
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=80225

[amit, 2011-04-01 05:15:12]

lgtm with a nit.

http://codereview.chromium.org/6759048/diff/1/base/process.h
File base/process.h (right):

http://codereview.chromium.org/6759048/diff/1/base/process.h#newcode28
base/process.h:28: const ProcessId kNullProcessId = NULL;
Since PricessId is a DWORD here, why not = 0?

[Jeff Bailey (chromium), 2011-04-01 05:26:09]

Thanks.  Will do one more pass through the try bots to be sure.

http://codereview.chromium.org/6759048/diff/1/base/process.h
File base/process.h (right):

http://codereview.chromium.org/6759048/diff/1/base/process.h#newcode28
base/process.h:28: const ProcessId kNullProcessId = NULL;
On 2011/04/01 05:15:12, amit wrote:
> Since PricessId is a DWORD here, why not = 0? 

Had to look up what a DWORD was.  Will change is.  I had put it as NULL before
just to match the previous definition, but this looks more correct.

[Ken Russell (switch to Gerrit), 2011-04-01 18:13:59]

LGTM