Remove unnecessary clearing of AX object cache in Document destructor.

Remove unnecessary clearing of AX object cache in Document destructor.

Only frame-attached Documents can have an AX object cache. All such
Documents will be explicitly detached; detach() will clear the AX
object cache. Thus clearing it again in the destructor ought to be
redundant -- leave in an assert to verify that this assumption will hold.

R=dmazzoni,haraken

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=194732

[sof, 2015-04-30 06:24:53]

sigbjornf@opera.com changed reviewers:
+ dmazzoni@chromium.org, haraken@chromium.org

[sof, 2015-04-30 06:24:53]

please take a look.

(following up on https://codereview.chromium.org/1089813004/#msg19 )

[dmazzoni, 2015-04-30 06:38:00]

lgtm

Makes sense! We'll learn soon enough if there's some obscure corner case where
this doesn't work.

[haraken, 2015-04-30 07:07:39]

LGTM

[sof, 2015-04-30 10:52:03]

Linux dbg bots aren't picking up anything new, so let's try.

[sof, 2015-04-30 10:52:08]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2015-04-30 10:52:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1116773003/1

[commit-bot: I haz the power, 2015-04-30 11:47:26]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=194732