Merge 171971 "Add back three deprecated DOM APIs removed from Ch..."

Merge 171971 "Add back three deprecated DOM APIs removed from Ch..."

> Add back three deprecated DOM APIs removed from Chrome 34
> 
> I added back the APIs and marked them as deprecated.
> I carefully checked to make sure they're using the
> same UseCounter ids as they were before.
> I did not add back the removed tests as it did not seem
> worth the hassle of dealing with the conflicts and
> rebaselines necessary due to the new deprecation messages.
> 
> These API removes are believed to have broken an unknown
> number of Chrome users in enterprise environments.
> Users in these settings are likely biased away from
> having "anonymous chrome usage data" reporting enabled
> meaning that their usage may not be reflected in the
> data displayed at chromestatus.com.  All we have currently
> is anecdotal data such as comments on mailing lists or
> in bugs reporting "100s of customers" from SAP
> as affected (crbug.com/364028).
> 
> These APIs were removed from Blink as "low hanging fruit".
> Each of these sees fewer than 1 view of every 1 million
> anonymously reported chrome views (well below our historical
> removal thresholds) and removing them is a step towards the
> larger removal of Attr nodes from the DOM (as has been
> proposed for the DOM 4 specification).
> 
> However the reward for the 99.99% of users who do not use
> these features is quite small. The risk to this unknown
> number of Blink "enterprise" users is likely too large
> to be worth the small code complexity reward at this time.
> 
> Adding these back for now, with deprecation messages.
> We'll likely remove these again from Blink in the future
> as usage of these features continues to decline and hopefully
> our measurement of enterprise usage improves.
> 
> BUG=341830, 341296, 353104, 364028
> 
> Review URL: https://codereview.chromium.org/243333003

TBR=eseidel@chromium.org