Retry "Replace RenderFullScreen with top layer"

This patch makes the Fullscreen API use the top layer, as per the latest
Fullscreen spec. This retry fixes some tests/expectations.

Previously landed as r165904 and r165710
Codereviews:
https://codereview.chromium.org/134753003/
https://codereview.chromium.org/139743005/

BUG=240576, 246077

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=166114

Review URL: https://codereview.chromium.org/142653003

git-svn-id: svn://svn.chromium.org/blink/trunk@166304 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL compiler: Fix types on [Custom] methods

This is a cleanup CL as part of finishing up the Python compiler.
The Python compiler checks types of methods, even if Custom, as that avoids
special-casing them. (We had the same issue with setters)

Perl instead early exits, so it ignores the types in [Custom] methods,
and several of these are invalid cruft.

The generic answer is to use |object| (which means "unspecified"), but
I've given the correct type when possible.

Also a line spacing fix for an old inconsistency between callback interfaces
and normal interfaces.

R=haraken

Review URL: https://codereview.chromium.org/143523016

git-svn-id: svn://svn.chromium.org/blink/trunk@166305 bbb929c8-8fbe-4397-9dbb-9b2b20218538