Remove broken optimization causing crashes on canary

The StyleResolver code long had an optimization to avoid
recomputing NodeRenderingContext and determineLinkState
when resolving style for the same node twice in a row.

Clearly we hit this case, since we managed to crash here,
but the optimization has always been broken.

We have lots of "node context" during resolve, and only some
of it we were always recomputing and some of it we weren't.
That division was made on the expense of the computation
not based on correctness. :)

When I grouped all of the state into a ElementResolveContext
I made it all either compute or not based on if the element
had changed.

Unfortunately that meant that if the elment had moved in the
DOM we were now using possibly stale pointers to its old
parent, etc.

Those stale pointers caused this crash, so I'm removing this
broken optmization.

This means the code is now possibly slower than before, but
definitely more correct than it's been in years.  I'm not
sure if we care about this correctness.  But if the recomputing
of the NodeRenderingContext and the LinkState are a problem
then we'll find a faster way to fix this.

BUG=260126
R=eae@chromium.org, esprehn@chromium.org, leviw@chromium.org

Review URL: https://codereview.chromium.org/19275003

git-svn-id: svn://svn.chromium.org/blink/trunk@154250 bbb929c8-8fbe-4397-9dbb-9b2b20218538