Use IDL argument default values in Document.idl

The 'whatToShow' and 'filter' arguments to the createNodeIterator() and
createTreeWalker() methods have default values in the specification.
Add those default values in Document.idl, and get rid of the extra
overloads of Document::createNodeIterator() and ::createTreeWalker().

BUG=258153

Review URL: https://codereview.chromium.org/342403007

git-svn-id: svn://svn.chromium.org/blink/trunk@176938 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove RuntimeEnableFeature flag for RepaintAfterLayout.

The non-RepaintAfterLayout code path has been removed and the chromium
command line flags cleaned up. This CL removes the runtime enabled feature
for RepaintAfterLayout which is the last piece of the cleanup.

BUG=385281

Review URL: https://codereview.chromium.org/350343005

git-svn-id: svn://svn.chromium.org/blink/trunk@176939 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL: [Unforgeable] on operation should imply DontDelete+ReadOnly

Previously, the only effect of [Unforgeable] on an operation was to put
the property on instance objects instead of on the prototype object.

All actual unforgeable operations -- Location's assign(), replace(),
reload(), toString() and valueOf() -- were additionally declared read-
only using [ReadOnly], which as a side-effect also made the properties
unconfigurable ("dont-delete").

This CL fixes [Unforgeable] on operations, and drops the then redundant
[ReadOnly] attributes from Location.idl. No CG changes.

BUG=

Review URL: https://codereview.chromium.org/350683004

git-svn-id: svn://svn.chromium.org/blink/trunk@176940 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove dead test

This test uses an API in testRunner which Chromium never added.

I think this was a test for a WebKit API for Mail.app.

My changes to the preloader are about to make this test even more flaky.

BUG=356292

Review URL: https://codereview.chromium.org/355753003

git-svn-id: svn://svn.chromium.org/blink/trunk@176941 bbb929c8-8fbe-4397-9dbb-9b2b20218538