Only check if a 'new' preference already exists in checking builds

Only check if a 'new' preference already exists in checking builds

PrefService::RegisterPref should never be called with an existing preference. It is a bug in Chromium if it is. The existing code checked this whether or not DCHECK checks were enabled. It isn't necessary to check this if DCHECKs are disabled.

BUG=158818
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=165372

[Anthony Berent, 2012-10-31 20:02:29]

This replaces some of changes that were originally part of
https://codereview.chromium.org/11307005/. It is, however, independent of any
changes to font preference registration, hence the separate CL.

[Bernhard Bauer, 2012-10-31 23:06:14]

https://codereview.chromium.org/11360014/diff/1/chrome/browser/prefs/pref_ser...
File chrome/browser/prefs/pref_service.cc (right):

https://codereview.chromium.org/11360014/diff/1/chrome/browser/prefs/pref_ser...
chrome/browser/prefs/pref_service.cc:790: DCHECK(FindPreference(path) == NULL)
<<
You could just write DCHECK(!FindPreference(path)) << ...

Also, << is broken on the following line. Also, alignment.

[Anthony Berent, 2012-11-01 10:25:24]

https://codereview.chromium.org/11360014/diff/1/chrome/browser/prefs/pref_ser...
File chrome/browser/prefs/pref_service.cc (right):

https://codereview.chromium.org/11360014/diff/1/chrome/browser/prefs/pref_ser...
chrome/browser/prefs/pref_service.cc:790: DCHECK(FindPreference(path) == NULL)
<<
On 2012/10/31 23:06:14, Bernhard Bauer wrote:
> You could just write DCHECK(!FindPreference(path)) << ...
> 
> Also, << is broken on the following line. Also, alignment.

Done.

[Bernhard Bauer, 2012-11-01 11:06:45]

lgtm

[commit-bot: I haz the power, 2012-11-01 11:10:38]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/aberent@chromium.org/11360014/5001

[commit-bot: I haz the power, 2012-11-01 14:41:31]

Change committed as 165372