Fix LayoutTreeBuilderTraversal limit checks when recursing.

Before this commit, we were checking for limit == 0, which is wrong given we
postdecrement (so when we actually run out of siblings we should keep limit
equal to -1).

BUG=657748
TEST=third_party/WebKit/Source/core/dom/LayoutTreeBuilderTraversalTest.cpp

Review-Url: https://codereview.chromium.org/2715353002
Cr-Commit-Position: refs/heads/master@{#453435}
2 files changed