commit 99c2073218960208c0f54de95b9c31ff9521ba46
author dominicc <dominicc@chromium.org> Tue Oct 04 00:35:22 2016
committer Commit bot <commit-bot@chromium.org> Tue Oct 04 00:39:24 2016
tree ca6b64aa56aaaf4f2025de35f705ee727cb52a32
parent 89b1e1527284754aa13e7a9fc5e7731105bc4886

Use the sibling limit to decide whether to create layout for whitespace

Text::textLayoutObjectIsNeeded is an optimization which avoids
creating layout objects for whitespace text nodes. However
LayoutTreeBuilderTraversal::nextSiblingLayoutObject traverses all
siblings. For long lists of N space-separated siblings, this
degenerates into an N^2 DOM walk. Oops.

Text::textLayoutObjectIsNeeded already has a sibling limit; this
passes the limit through to
prevSiblingLayoutObject/nextSiblingLayoutObject.

BUG=650938

Review-Url: https://codereview.chromium.org/2379483002
Cr-Commit-Position: refs/heads/master@{#422631}