Revert "Rework pseudoStyleCacheIsInvalid to be simpler and more efficient"

This reverts commit http://src.chromium.org/viewvc/blink/?view=revision&revision=161887

This whole pseudo style cache system doesn't work like how I thought. It needs more investigation.

BUG=319040
TBR=inferno@chromium.org

Review URL: https://codereview.chromium.org/61793020

git-svn-id: svn://svn.chromium.org/blink/trunk@162004 bbb929c8-8fbe-4397-9dbb-9b2b20218538