Revert "Separate the scrolling code out of RenderLayer"

The change has caused 2 very bad and widespread hangs
on Canary inside FrameView::removeScrollableArea and
EventHandler::associatedScrollableArea.

Reverting the original change and the crash fix (but leaving
the tests in the tree) so that I can figure out what's wrong
with the change.

TBR=vollick@chromium.org,esprehn@chromium.org
BUG=264588

Review URL: https://codereview.chromium.org/20779002

git-svn-id: svn://svn.chromium.org/blink/trunk@154998 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Don't assume so easily that RenderStyle data can be shared.

An element can only share RenderStyle data with another element if
BOTH are cacheable. The element that's already in the cache is
obviously cacheable, but we also need to figure out whether the
element that wants to use data from the cache is cachable.

Additionally, get rid of the Element* argument from
applyMatchedProperties(), since it's already part of the state object
passed to that method.

BUG=236329

Review URL: https://chromiumcodereview.appspot.com/20560008

git-svn-id: svn://svn.chromium.org/blink/trunk@154999 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Re-rebaseline fast/selectors/unqualified-hover-strict.html after bad auto-rebaseline

TBR=ojan

Review URL: https://codereview.chromium.org/20784002

git-svn-id: svn://svn.chromium.org/blink/trunk@155000 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert "Distinguish actions registered with setTimeout() and setInterval()."

This reverts https://src.chromium.org/viewvc/blink?view=rev&revision=154624

Reason: suspected as the cause of OOM crashes.

BUG=230705,263503
TBR=haraken

Review URL: https://codereview.chromium.org/20759003

git-svn-id: svn://svn.chromium.org/blink/trunk@155001 bbb929c8-8fbe-4397-9dbb-9b2b20218538