Rename scheduleLayerUpdate now that it's only used for SVG filters.

This method is all sorts of badness. It leads to strange chicken-egg
bugs because people don't think that you will need to update layer
state after the layout has completed. 

FrameView::updateLayoutAndStyleIfNeededRecursive needs to do a second
style recalc and layout just for this and in theory it should probably
do a while loop there to get this right.

Now that we've removed all the non-SVG filter callers of this function,
rename it to something scary so that people won't add new callers.

Review URL: https://codereview.chromium.org/319613004

git-svn-id: svn://svn.chromium.org/blink/trunk@175618 bbb929c8-8fbe-4397-9dbb-9b2b20218538