IDL compiler: Extended attributes on partial interfaces

This adds support and tests for the 4 extended attributes on partial interfaces:
* [Conditional]
* [ImplementedAs]
* [PerContextEnabled]
* [RuntimeEnabled]
(Extra test file needed to avoid conflicts.)

This completes partial interfaces!

Docs:
https://sites.google.com/a/chromium.org/dev/blink/webidl/blink-idl-extended-attributes#TOC-Partial-interfaces

BUG=239771
R=haraken
NOTRY=true

Review URL: https://codereview.chromium.org/133273009

git-svn-id: svn://svn.chromium.org/blink/trunk@165296 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Supply "replayXHR" with appropriate execution context.

BUG=332700

Review URL: https://codereview.chromium.org/134643004

git-svn-id: svn://svn.chromium.org/blink/trunk@165297 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Updating <object> upon changing "data", "classid", "type" attributes.

If an HTMLObjectElement's "type", "data", or "classid" attributes are
dynamically modified, trigger a refresh of the element. Following the
rules given in

  http://www.whatwg.org/specs/web-apps/current-work/#dom-object-data

(cf. "Whenever one of the following conditions occur:")

R=abarth,eseidel,esprehn
BUG=123536
TEST=fast/dom/HTMLObjectElement/update-data

Review URL: https://codereview.chromium.org/135103003

git-svn-id: svn://svn.chromium.org/blink/trunk@165298 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Count DOMImplementation.hasFeature usage and cases where it returns false

This is in order to support the spec discussion:
http://lists.w3.org/Archives/Public/www-dom/2014JanMar/0031.html
http://lists.w3.org/Archives/Public/www-svg/2014Jan/0042.html

BUG=335301

Review URL: https://codereview.chromium.org/141363002

git-svn-id: svn://svn.chromium.org/blink/trunk@165299 bbb929c8-8fbe-4397-9dbb-9b2b20218538