Omnibox: Clobber HQP Cache File when user mucks with history

Omnibox: Clobber HQP Cache File when user mucks with history

TBR=sky
(as usual for omnibox HistoryQuick provider stuff)

Test: see repro steps on bug.

BUG=400940
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=288515

[Mark P, 2014-08-08 19:25:24]

As discussed.  Please take a look.

thanks,
mark

[Peter Kasting, 2014-08-08 20:22:02]

LGTM

The new comment seems a little repetitive in its verbosity, but I don't have a
concrete suggestion about it.

[Mark P, 2014-08-08 20:24:08]

The CQ bit was checked by mpearson@chromium.org

[commit-bot: I haz the power, 2014-08-08 20:25:51]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mpearson@chromium.org/455003002/1

[commit-bot: I haz the power, 2014-08-09 01:53:30]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)
  win_chromium_rel on tryserver.chromium.win
(http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel/...)

[commit-bot: I haz the power, 2014-08-09 02:00:10]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-08-09 02:00:11]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[Mark P, 2014-08-09 03:25:53]

The CQ bit was checked by mpearson@chromium.org

[commit-bot: I haz the power, 2014-08-09 03:27:39]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mpearson@chromium.org/455003002/1

[commit-bot: I haz the power, 2014-08-09 05:46:11]

Change committed as 288515