Remove deferred repaint code from FrameView

This code depends on the REPAINT_THROTTLING define which is disabled.
The repaint throttling makes the FrameView code more complex than it needs to
be. Removing it simplifies the code quite a bit.

R=esprehn, adamk

Review URL: https://codereview.chromium.org/140913002

git-svn-id: svn://svn.chromium.org/blink/trunk@165589 bbb929c8-8fbe-4397-9dbb-9b2b20218538