Revert "Don't invalidate scrolling container layer when scrolling contents need invalidation"

Revert "Don't invalidate scrolling container layer when scrolling contents need invalidation"

This reverts commit 20feb3edc199015a96b39c081d50a083cf39ac87.

We still can't clearly distinguish invalidations for container layer
and scrolling contents layer. For example, crbug.com/429845, the shadow
div of an editor is scrollable, but the editor invalidates itself to
update selection, caret and content; With the change, the invalidation
will happen on the container only.

Revert first and try to find a good solution.

Perhaps we can just wait for slimming paint.

Still keep the layout tests added in the original change but will be
rebaselined.

TBR=vollick@chromium.org,chrishtr@chromium.org,dsinclair@chromium.org
BUG=416535, 429845
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184838

[Xianzhu, 2014-11-04 17:32:50]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2014-11-04 17:33:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/701873002/1

[commit-bot: I haz the power, 2014-11-04 20:36:07]

Committed patchset #1 (id:1) as 184838