Remove Node.prefix so it's no longer visible to script.

This is in line with DOM4 <http://dom.spec.whatwg.org/#node>

prefix remains on Attr and Element, which is the only place it does
something useful, although setting prefixes will probably be removed
entirely.

BUG=325922

Review URL: https://codereview.chromium.org/126713004

git-svn-id: svn://svn.chromium.org/blink/trunk@164729 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL compiler: Callback interfaces as argument type (initial)

Plumbing is analogous implementation to [ImplementedAs] on types.
There are various places in the CG that check for callback interfaces;
this does the plumbing (is_callback_interface) and the simplest CG change.
Follow-ups will include other CG cases.

BUG=239771
R=haraken

Review URL: https://codereview.chromium.org/127103005

git-svn-id: svn://svn.chromium.org/blink/trunk@164730 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Layout support for new circle shape syntax

Implement support for doing layout with the new circle shape syntax,
including basic animation support.

Add a few tests for the new circle syntax. The old tests in
LayoutTests/csswg will be removed when the old syntax is removed.

Also update existing shape-inside, animation, and clip-path tests to
test the new syntax.

Patch by Bem Jones-Bey.

BUG=322165

Review URL: https://codereview.chromium.org/115253003

git-svn-id: svn://svn.chromium.org/blink/trunk@164731 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL compiler: Nullable callback interface arguments

One use:
Source/core/dom/DataTransferItem.idl:
[CallWith=ExecutionContext] void getAsString(StringCallback? callback);

BUG=239771
R=haraken
NOTRY=true

Review URL: https://codereview.chromium.org/127773002

git-svn-id: svn://svn.chromium.org/blink/trunk@164732 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL compiler: Optional callback interface arguments

(42 uses. *42*!)

BUG=239771
R=haraken
NOTRY=true

Review URL: https://codereview.chromium.org/127793002

git-svn-id: svn://svn.chromium.org/blink/trunk@164733 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL compiler: Overloaded methods with callback interface arguments

One use:
RTCPeerConnection.idl: addIceCandidate()

BUG=239771
R=haraken
NOTRY=true

Review URL: https://codereview.chromium.org/130423002

git-svn-id: svn://svn.chromium.org/blink/trunk@164734 bbb929c8-8fbe-4397-9dbb-9b2b20218538
IDL compiler: [ExceptionState] with callback interface arguments

Test-only change (exercise other code path); code already implemented.
This finishes callback interface arguments.

BUG=239771
TBR=haraken
NOTRY=true

Review URL: https://codereview.chromium.org/130453002

git-svn-id: svn://svn.chromium.org/blink/trunk@164735 bbb929c8-8fbe-4397-9dbb-9b2b20218538