Don't always fully repaint on viewport resize

This is based on https://codereview.chromium.org/265703012/
and https://codereview.chromium.org/270663003/.

- Don't force repaint on FrameView::setNeedsLayout()
- Only invalidate if necessary in RenderView::layout()

BUG=258219
TEST=fast/repaint/window-resize-*.html

Review URL: https://codereview.chromium.org/275543003

git-svn-id: svn://svn.chromium.org/blink/trunk@174468 bbb929c8-8fbe-4397-9dbb-9b2b20218538