Remove complexity related to m_cachedElementsArrayOffset from LiveNodeListBase

Remove complexity related to m_cachedElementsArrayOffset from LiveNodeListBase

Remove complexity related to m_cachedElementsArrayOffset from LiveNodeListBase
and HTMLCollection. The complexity is moved to HTMLFormControlsCollection
which is the only type that actually needs to cache this offset.

The code in LiveNodeListBase / HTMLCollection is overly complex and this is one
step towards improving the situation.

This change is a partial merge of WebKit r158758 by <antti@apple.com>;.

R=abarth, esprehn, eseidel

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=164452

[Inactive, 2014-01-03 15:50:05]

Post-holidays ping review? :)

[eseidel, 2014-01-03 17:45:00]

lgtm

https://codereview.chromium.org/113653006/diff/170001/Source/core/dom/LiveNod...
File Source/core/dom/LiveNodeList.cpp (right):

https://codereview.chromium.org/113653006/diff/170001/Source/core/dom/LiveNod...
Source/core/dom/LiveNodeList.cpp:57: static_cast<const
HTMLCollection*>(this)->invalidateIdNameCacheMaps();
Bleh.

[commit-bot: I haz the power, 2014-01-03 17:45:05]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ch.dumez@samsung.com/113653006/170001

[commit-bot: I haz the power, 2014-01-03 17:52:18]

Change committed as 164452