Move LineLayoutState class into rendering/line

As a part of RenderBlockLineLayout.cpp refactoring, I'm moving out LineLayoutState into a separate
file. I'm doing the refactoring step by step, the progress is tracked under 316347 tracking issue.

BUG=334363

Review URL: https://codereview.chromium.org/138773002

git-svn-id: svn://svn.chromium.org/blink/trunk@165105 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add a trace for RenderLayer::updateLayerPositionsAfterLayout.

I'm seeing this taking up a big portion of FrameView::layout in my trace.

Review URL: https://codereview.chromium.org/138823003

git-svn-id: svn://svn.chromium.org/blink/trunk@165106 bbb929c8-8fbe-4397-9dbb-9b2b20218538