Revert 169395 "Set geometry dirty bits on composited layer mappi..."

Causing virtual/softwarecompositing/squashing/squashed-layer-loses-graphicslayer.html to fail.

> Set geometry dirty bits on composited layer mappings when updating squashed layers.
> 
> The lack of setting geometry dirty bits in these cases is wrong. However, at the moment it is masked by setting needs geometry dirty bits more globally upwards in the system. When that is cleaned up these targeted ones will be in place.
> 
> BUG=
> 
> Review URL: https://codereview.chromium.org/200623006

TBR=chrishtr@chromium.org

Review URL: https://codereview.chromium.org/201153013

git-svn-id: svn://svn.chromium.org/blink/trunk@169402 bbb929c8-8fbe-4397-9dbb-9b2b20218538