Bring back fast paths for HTMLTagCollection / ClassCollection's access

Bring back fast paths for HTMLTagCollection / ClassCollection's access.
Those were removed in r166263, when switching them from LiveNodeList to
HTMLCollection type. r166263 caused Dromaeo's dom-query test to regress by
~12% according to our build bots and this CL is an attempt to address the
issue. Locally, I see a 3-4% improvement on dom-query but I am hoping the
bots get better results.

R=arv, haraken, adamk
BUG=340325

Review URL: https://codereview.chromium.org/138653004

git-svn-id: svn://svn.chromium.org/blink/trunk@166427 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix scroll restore when doing a same-document back navigation.

http://src.chromium.org/viewvc/blink?revision=164641&view=revision broke it.

There's an old, nasty hack in WebFrameImpl::currentHistoryItem() where we
save state to the current history item before we return it to the embedder.
r164641 slightly expanded the case where we do so, causing us to clobber
scroll position before restoring it. I'm suspicious that saving the scroll
state before returning it is unnecessary, or at the very least is a
workaround for a case where we aren't saving the state earlier.

Ergo, remove the hack, that we may fix the current issue
and see what monsters lurk beneath.

BUG=339822
TEST=http/tests/navigation/same-document-scroll-position.html (revised)

Review URL: https://codereview.chromium.org/137803010

git-svn-id: svn://svn.chromium.org/blink/trunk@166428 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Removing unnecessary save/restore in print code.

There is no need to save when we will do another before restoring.

This is not any kind of performance win because it only happens
while printing. Another potential problem is flagged with a comment
to prevent future confusion.

R=abarth@chromium.org, fmalita@chromium.org
BUG=334904

Review URL: https://codereview.chromium.org/137833017

git-svn-id: svn://svn.chromium.org/blink/trunk@166429 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove default arguments from viewLogicalHeight/Width.

They're never used.

Review URL: https://codereview.chromium.org/149293005

git-svn-id: svn://svn.chromium.org/blink/trunk@166430 bbb929c8-8fbe-4397-9dbb-9b2b20218538