Generalized fix for serialization error/reset issues

Merge to m56: Generalized fix for serialization error/reset issues

Whenever we see an AX tree fail to unserialize, request it be reset on the source end.

TEST=in hotrod, repeatedly toggle on/off ChromeVox. Verify that we re-populate the tree when we get any events (e.g. focus).
BUG=667819
TBR=dtseng@chromium.org

Review-Url: https://codereview.chromium.org/2522033002
Cr-Commit-Position: refs/heads/master@{#433985}
(cherry picked from commit 38c63d7344c76d9fa58c84db6112daebbfefd3ab)

Committed: https://chromium.googlesource.com/chromium/src/+/a316708a12944f6222b0bba88dfddc767ffe893f

[David Tseng, 2016-12-01 17:14:28]

Description was changed from

==========
Generalized fix for serialization error/reset issues

Whenever we see an AX tree fail to unserialize, request it be reset on the
source end.

TEST=in hotrod, repeatedly toggle on/off ChromeVox. Verify that we re-populate
the tree when we get any events (e.g. focus).
BUG=667819

Review-Url: https://codereview.chromium.org/2522033002
Cr-Commit-Position: refs/heads/master@{#433985}
(cherry picked from commit 38c63d7344c76d9fa58c84db6112daebbfefd3ab)
==========

to

==========
Merge to m56: Generalized fix for serialization error/reset issues

Whenever we see an AX tree fail to unserialize, request it be reset on the
source end.

TEST=in hotrod, repeatedly toggle on/off ChromeVox. Verify that we re-populate
the tree when we get any events (e.g. focus).
BUG=667819
TBR=dtseng@chromium.org

Review-Url: https://codereview.chromium.org/2522033002
Cr-Commit-Position: refs/heads/master@{#433985}
(cherry picked from commit 38c63d7344c76d9fa58c84db6112daebbfefd3ab)
==========

[David Tseng, 2016-12-01 17:19:34]

Description was changed from

==========
Merge to m56: Generalized fix for serialization error/reset issues

Whenever we see an AX tree fail to unserialize, request it be reset on the
source end.

TEST=in hotrod, repeatedly toggle on/off ChromeVox. Verify that we re-populate
the tree when we get any events (e.g. focus).
BUG=667819
TBR=dtseng@chromium.org

Review-Url: https://codereview.chromium.org/2522033002
Cr-Commit-Position: refs/heads/master@{#433985}
(cherry picked from commit 38c63d7344c76d9fa58c84db6112daebbfefd3ab)
==========

to

==========
Merge to m56: Generalized fix for serialization error/reset issues

Whenever we see an AX tree fail to unserialize, request it be reset on the
source end.

TEST=in hotrod, repeatedly toggle on/off ChromeVox. Verify that we re-populate
the tree when we get any events (e.g. focus).
BUG=667819
TBR=dtseng@chromium.org

Review-Url: https://codereview.chromium.org/2522033002
Cr-Commit-Position: refs/heads/master@{#433985}
(cherry picked from commit 38c63d7344c76d9fa58c84db6112daebbfefd3ab)

Committed:
https://chromium.googlesource.com/chromium/src/+/a316708a12944f6222b0bba88dfd...
==========

[David Tseng, 2016-12-01 17:19:35]

Committed patchset #1 (id:1) manually as
a316708a12944f6222b0bba88dfddc767ffe893f (presubmit successful).