IDL: Improve "includes for type" mechanism in various ways

IDL: Improve "includes for type" mechanism in various ways

- Optionally pass extended attributes along with the type, so that the
  includes generated can depend on it. (This is not needed now, but will
  be in the future.)

- Add includes for the types of method arguments, getters and setters.

- Cleanup some (now) redundant calls to add_includes_for_type() in
  v8_types.py that interfered with the next item.

- Don't add includes relating to "invisible" methods. Invisible methods
  are those that come from partial interfaces, and that won't actually
  be implemented in the compilation unit being generated. Adding such
  includes meant that files under bindings/core/ would sometimes include
  headers from bindings/modules/ (without depending on the contents of
  those headers).

BUG=358074
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=193787

[Jens Widell, 2015-04-15 10:43:31]

jl@opera.com changed reviewers:
+ haraken@chromium.org, tasak@google.com

[Jens Widell, 2015-04-15 10:43:32]

PTAL

tasak@: I don't know to what degree this actually helps the componentization
effort, but including modules/ headers in core/ source files is at least wrong
by policy. With this applied, there are no such includes in generated core/
files, and since things still compile, apparently no wrong dependencies either.

[haraken, 2015-04-15 11:03:10]

Looks like a nice clean-up. LGTM.

[Jens Widell, 2015-04-15 11:33:19]

The CQ bit was checked by jl@opera.com

[commit-bot: I haz the power, 2015-04-15 11:33:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1086113002/1

[commit-bot: I haz the power, 2015-04-15 12:58:01]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=193787