IndexedDB: Regression test for db enumeration including failed opens

IndexedDB: Regression test for db enumeration including failed opens

Bug fixed on the Chromium side, just adding a layout test as well
for full coverage.

BUG=395472
R=cmumford@chromium.org

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=180103

[jsbell, 2014-08-12 18:27:21]

cmumford@ - please take a look?

[cmumford, 2014-08-12 18:59:05]

lgtm

[jsbell, 2014-08-12 18:59:39]

The CQ bit was checked by jsbell@chromium.org

[commit-bot: I haz the power, 2014-08-12 19:00:50]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jsbell@chromium.org/462153002/1

[commit-bot: I haz the power, 2014-08-12 20:46:20]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  linux_blink_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/2...)
  mac_blink_compile_dbg on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_compile_dbg/bu...)
  win_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/22345)

[commit-bot: I haz the power, 2014-08-12 21:45:19]

Change committed as 180103