Fix flakiness in DumpAccessibilityTree tests with iframes

Fix flakiness in DumpAccessibilityTree tests with iframes

I found three sources of flakiness in DumpAccessibilityTree tests with iframes:
1. Enabled a check that all frames have loaded before dumping the accessibility
   tree. Previously it was only possible to do that check on out-of-process
   iframes, but now that bug 532249 is fixed we can do that check on all
   iframes.
2. Removed code to check if each frame's surface is ready. It's no longer
   necessary now that bug 618120 is fixed, and it was causing flakiness.
3. The scroll max for the main page is sometimes flaky because it changes
   asynchronously after the page loads. Modified the tests to not dump
   scroll mins and maxes.

Re-enables several disabled tests. We may be able to enable a few more in
a follow-up.

BUG=622387
Committed: https://crrev.com/fadb58864d3a99cd09b89d31994d4286f4cb60d2
Cr-Commit-Position: refs/heads/master@{#416103}

[dmazzoni, 2016-08-31 18:20:41]

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

[dmazzoni, 2016-08-31 18:20:53]

dmazzoni@chromium.org changed reviewers:
+ nektar@chromium.org

[commit-bot: I haz the power, 2016-08-31 18:21:27]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-31 19:32:45]

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

[commit-bot: I haz the power, 2016-08-31 19:32:46]

Dry run: This issue passed the CQ dry run.

[nektarios, 2016-09-01 20:38:48]

lgtm

[dmazzoni, 2016-09-01 21:39:57]

The CQ bit was checked by dmazzoni@chromium.org

[commit-bot: I haz the power, 2016-09-01 21:40:51]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-01 22:57:14]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-01 22:58:54]

Description was changed from

==========
Fix flakiness in DumpAccessibilityTree tests with iframes

I found three sources of flakiness in DumpAccessibilityTree tests with iframes:
1. Enabled a check that all frames have loaded before dumping the accessibility
   tree. Previously it was only possible to do that check on out-of-process
   iframes, but now that bug 532249 is fixed we can do that check on all
   iframes.
2. Removed code to check if each frame's surface is ready. It's no longer
   necessary now that bug 618120 is fixed, and it was causing flakiness.
3. The scroll max for the main page is sometimes flaky because it changes
   asynchronously after the page loads. Modified the tests to not dump
   scroll mins and maxes.

Re-enables several disabled tests. We may be able to enable a few more in
a follow-up.

BUG=622387
==========

to

==========
Fix flakiness in DumpAccessibilityTree tests with iframes

I found three sources of flakiness in DumpAccessibilityTree tests with iframes:
1. Enabled a check that all frames have loaded before dumping the accessibility
   tree. Previously it was only possible to do that check on out-of-process
   iframes, but now that bug 532249 is fixed we can do that check on all
   iframes.
2. Removed code to check if each frame's surface is ready. It's no longer
   necessary now that bug 618120 is fixed, and it was causing flakiness.
3. The scroll max for the main page is sometimes flaky because it changes
   asynchronously after the page loads. Modified the tests to not dump
   scroll mins and maxes.

Re-enables several disabled tests. We may be able to enable a few more in
a follow-up.

BUG=622387

Committed: https://crrev.com/fadb58864d3a99cd09b89d31994d4286f4cb60d2
Cr-Commit-Position: refs/heads/master@{#416103}
==========

[commit-bot: I haz the power, 2016-09-01 22:58:55]

Patchset 1 (id:??) landed as
https://crrev.com/fadb58864d3a99cd09b89d31994d4286f4cb60d2
Cr-Commit-Position: refs/heads/master@{#416103}