Skip the whole shadow tree when its tabindex is -1.

Skip the whole shadow tree when its tabindex is -1.

If a shadow host, which has tabindex=-1, is specified as 'delegatesFocus=true'
by its shadow root, the whole shadow tree should be skipped for tab navigation order.

Design doc:
https://docs.google.com/document/d/1k93Ez6yNSyWQDtGjdJJqTBPmljk9l2WS3JTe5OHHB50/edit

BUG=496005
TEST=fast/dom/shadow/focus-navigation-with-delegatesFocus.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=197251

[kochi, 2015-06-17 06:45:52]

Patchset #2 (id:20001) has been deleted

[kochi, 2015-06-17 06:46:01]

Patchset #2 (id:40001) has been deleted

[kochi, 2015-06-17 06:47:08]

The CQ bit was checked by kochi@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-06-17 06:47:21]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1187273002/60001

[kochi, 2015-06-17 07:11:49]

kochi@chromium.org changed reviewers:
+ hayato@chromium.org

[kochi, 2015-06-17 07:11:50]

PTAL

https://codereview.chromium.org/1187273002/diff/60001/Source/core/page/FocusC...
File Source/core/page/FocusController.cpp (left):

https://codereview.chromium.org/1187273002/diff/60001/Source/core/page/FocusC...
Source/core/page/FocusController.cpp:563: if
(!isNonFocusableFocusScopeOwner(*found))
In the previous CL[1], I added this line (563) but this code was wrong.

Lines 557-564 are executed when |found| is a shadow host and its
|delegatesFocus|
is true.  It also implies |found| is not a UA shadow root (as no one uses
|delegatesFocus| so far), thus on line 557 isShadowHostWithoutCustomFocusLogic()
returned always true, and lines 563-564 were never executed.

[1]:
https://codereview.chromium.org/1174893002/diff/40001/Source/core/page/FocusC...

https://codereview.chromium.org/1187273002/diff/60001/Source/core/page/FocusC...
File Source/core/page/FocusController.cpp (right):

https://codereview.chromium.org/1187273002/diff/60001/Source/core/page/FocusC...
Source/core/page/FocusController.cpp:569: // Now |found| is on a non focusable
scope owner (either shadow host or <shadow>)
The comment was wrong ;(

https://codereview.chromium.org/1187273002/diff/60001/Source/core/page/FocusC...
Source/core/page/FocusController.cpp:575: return
findFocusableElementRecursivelyForward(scope, found);
This chunk does not change the logic, but aligned style with lines 559-561.
It can be extracted to a function, but this is small and I keep them.

[commit-bot: I haz the power, 2015-06-17 09:48:30]

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

[commit-bot: I haz the power, 2015-06-17 09:48:31]

Dry run: Try jobs failed on following builders:
  win_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/66975)

[hayato, 2015-06-17 10:18:40]

lgtm

[kochi, 2015-06-17 10:26:15]

The CQ bit was checked by kochi@chromium.org

[commit-bot: I haz the power, 2015-06-17 10:26:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1187273002/60001

[commit-bot: I haz the power, 2015-06-17 11:23:14]

Committed patchset #2 (id:60001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=197251