Second reland: Fix incorrect sign in scroll and content box offset in absoluteToLocalPoint.

Second reland:

Fix incorrect sign in scroll and content box offset in absoluteToLocalPoint.
Also, refactored the tests a bit to share more code for iframes and reduce boilerplate. (https://codereview.chromium.org/1511183003)

Now passes unittests on Android, by making the scrollbars display:none.

TBR=wangxianzhu@chromium.org
BUG=566238
Committed: https://crrev.com/c77fbd5867bd43264ca59eb40aaebbf7d574d876
Cr-Commit-Position: refs/heads/master@{#364419}

[chrishtr, 2015-12-10 17:29:16]

Description was changed from

==========
none


Reland:

Fix incorrect sign in scroll and content box offset in absoluteToLocalPoint.
Also, refactored the tests a bit to share more code for iframes and reduce
boilerplate. (https://codereview.chromium.org/1504363004)

Now compiles with Oilpan.

TBR=wangxianzhu@chromium.org
BUG=566238

Committed: https://crrev.com/437435aad459dd054b5c0e9a7e5b09ebcac6d902
Cr-Commit-Position: refs/heads/master@{#364198}

patch from issue 1511183003 at patchset 1 (http://crrev.com/1511183003#ps1)
==========

to

==========
Second reland:

Fix incorrect sign in scroll and content box offset in absoluteToLocalPoint.
Also, refactored the tests a bit to share more code for iframes and reduce
boilerplate. (https://codereview.chromium.org/1511183003)

Now passes unittests on Android.

TBR=wangxianzhu@chromium.org
BUG=566238
==========

[chrishtr, 2015-12-10 17:29:49]

Description was changed from

==========
Second reland:

Fix incorrect sign in scroll and content box offset in absoluteToLocalPoint.
Also, refactored the tests a bit to share more code for iframes and reduce
boilerplate. (https://codereview.chromium.org/1511183003)

Now passes unittests on Android.

TBR=wangxianzhu@chromium.org
BUG=566238
==========

to

==========
Second reland:

Fix incorrect sign in scroll and content box offset in absoluteToLocalPoint.
Also, refactored the tests a bit to share more code for iframes and reduce
boilerplate. (https://codereview.chromium.org/1511183003)

Now passes unittests on Android, by making the scrollbars display:none.

TBR=wangxianzhu@chromium.org
BUG=566238
==========

[chrishtr, 2015-12-10 17:29:53]

The CQ bit was checked by chrishtr@chromium.org

[commit-bot: I haz the power, 2015-12-10 17:30:14]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1516893002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1516893002/1

[commit-bot: I haz the power, 2015-12-10 19:08:24]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-12-10 19:10:08]

Description was changed from

==========
Second reland:

Fix incorrect sign in scroll and content box offset in absoluteToLocalPoint.
Also, refactored the tests a bit to share more code for iframes and reduce
boilerplate. (https://codereview.chromium.org/1511183003)

Now passes unittests on Android, by making the scrollbars display:none.

TBR=wangxianzhu@chromium.org
BUG=566238
==========

to

==========
Second reland:

Fix incorrect sign in scroll and content box offset in absoluteToLocalPoint.
Also, refactored the tests a bit to share more code for iframes and reduce
boilerplate. (https://codereview.chromium.org/1511183003)

Now passes unittests on Android, by making the scrollbars display:none.

TBR=wangxianzhu@chromium.org
BUG=566238

Committed: https://crrev.com/c77fbd5867bd43264ca59eb40aaebbf7d574d876
Cr-Commit-Position: refs/heads/master@{#364419}
==========

[commit-bot: I haz the power, 2015-12-10 19:10:09]

Patchset 1 (id:??) landed as
https://crrev.com/c77fbd5867bd43264ca59eb40aaebbf7d574d876
Cr-Commit-Position: refs/heads/master@{#364419}