Make CSSValueList.item() index argument mandatory

Make CSSValueList.item() index argument mandatory as per the specification:
http://www.w3.org/TR/DOM-Level-2-Style/css.html#CSS-CSSValueList

This behavior is consistent with Firefox 23. I wasn't able to test on IE10.
It is confusing what the return value is supposed to be if the index is
omitted.

BUG=

Review URL: https://chromiumcodereview.appspot.com/23526011

git-svn-id: svn://svn.chromium.org/blink/trunk@157057 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix case handling of FeatureNames in EnabledAtRuntime IDL extended attribute

Runtime enabled features are in UpperCamelCase, and should be written
thus in IDL files. Associated Blink method names are in lowerCamelCase,
so these are lowercased in scripts.
Unfortunately, there were a number of bugs in the scripts where they
failed to lowercase properly, and thus in the IDL files there were lots
of featureNames instead of FeatureNames to hack around this.
This had been causing some developer pain and made the files confusing
and inconsistent.

This fixes the scripts (2 bindings, 1 core), and fixes all IDL files
to have UpperCamelCase FeatureNames.

Depends on previous CL (waiting to land):
Give explicit argument to EnabledAtRuntime (IDL extended attribute)
https://codereview.chromium.org/23667002/

Review URL: https://chromiumcodereview.appspot.com/23623005

git-svn-id: svn://svn.chromium.org/blink/trunk@157058 bbb929c8-8fbe-4397-9dbb-9b2b20218538
TEST COMPLETE does not appear at the end of spellchecking tests

Fix this by setting 'jsTestIsAsync = true' and calling finishJSTest()
when the asynchronous spellchecking tests end.

WebKit changeset: http://trac.webkit.org/changeset/154869

In addition, this CL adjusts the newly created Blink's spelling tests
to dump the messages in right order.

This change showed a bug in spellcheck-disable-enable.html that starts
failing after turning on asynchronous spell checker, added it to
TestExpectations (see crbug.com/282426 for more details).

Some spellchecking tests do not verify anything asynchronously.
Call the body of 'test()' directly instead of calling 'test()'
in onload event. It ensures that the js-test-post.js is invoked at
the end and the messages order is correct.

BUG=

Review URL: https://chromiumcodereview.appspot.com/23444027

git-svn-id: svn://svn.chromium.org/blink/trunk@157059 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rename the enums used for TimingFunction types and CubicBezierTimingFunction sub-types

This improves readability.

R=dstockwell

Review URL: https://chromiumcodereview.appspot.com/23591014

git-svn-id: svn://svn.chromium.org/blink/trunk@157060 bbb929c8-8fbe-4397-9dbb-9b2b20218538