IDL compiler: EventHandler attributes in Node interfaces

Add test file for Node interfaces.
Also simplification of the hard-coded DOM Node list;
I should be able to eliminate this in Python thanks to interfaces_info
(in followup).

BUG=239771
R=haraken

Review URL: https://codereview.chromium.org/131013002

git-svn-id: svn://svn.chromium.org/blink/trunk@164761 bbb929c8-8fbe-4397-9dbb-9b2b20218538