Invalidate RenderBlockFlow with inline children when doing full layout

The bug is a regression caused by my change "Don't force full
repaint on size change in style"
(https://codereview.chromium.org/312193004/).

Now force repaint when text flow changes.

BUG=388812
TEST=fast/repaint/inline-reflow.html

Review URL: https://codereview.chromium.org/348843012

git-svn-id: svn://svn.chromium.org/blink/trunk@176954 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Don't force layout on imageChanged when the size doesn't change

Previously we'd force a layout when an image changes if it has a
percent logical [max|min] width even if it didn't change size.
This means an animated gif can trigger constant layout.

This patch is similar to https://codereview.chromium.org/277303003/

BUG=388471

Review URL: https://codereview.chromium.org/359513002

git-svn-id: svn://svn.chromium.org/blink/trunk@176955 bbb929c8-8fbe-4397-9dbb-9b2b20218538