If an element's layer with accelerated children and border-radius reaches the compositing state of |paintsIntoCompositedAncestor|, painting is no longer performed due to the early bail in CompositedLayerMapping::doPaintTask, which also triggers a debug assert.

The issue was caused by adding support for correctly rendering layers having border-radius and overflow-hidden using masks, by the time the |paintsIntoCompositedAncestor| compositing state was removed. However, this compositing state was reintroduced, causing the problem at matter.

The solution for this consists in assigning a backing store to layers with border-radius and overflow hidden.

BUG=330977

Review URL: https://codereview.chromium.org/125963002

git-svn-id: svn://svn.chromium.org/blink/trunk@164833 bbb929c8-8fbe-4397-9dbb-9b2b20218538
White spaces between nowrap and normal inlines should break the line.

If we have left a no-wrap inline and entered an autowrap inline while ignoring
spaces then we need to mark the start of the autowrap inline as a potential line
break now.

BUG=332431

Review URL: https://codereview.chromium.org/128923002

git-svn-id: svn://svn.chromium.org/blink/trunk@164834 bbb929c8-8fbe-4397-9dbb-9b2b20218538