Simple line layout: Reset LineState when starting a new line.

Simple line layout: Reset LineState when starting a new line.
https://bugs.webkit.org/show_bug.cgi?id=140789

Reviewed by Antti Koivisto.

Reset LineState when starting a new line to ensure we always
start with a clean state.

No change in functionality.

* rendering/SimpleLineLayout.cpp:
(WebCore::SimpleLineLayout::updateLineConstrains):
(WebCore::SimpleLineLayout::initializeNewLine):
(WebCore::SimpleLineLayout::splitFragmentToFitLine):
(WebCore::SimpleLineLayout::createTextRuns):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@178964 268f45cc-cd09-0410-ab3c-d52691b4dbfc