IDL compiler: always include GetPtr.h and RefPtr.h

These headers are used by all meaningful IDL files
(any interface type argument);
the current logic is twisty and reflects implementation of Perl and Python
(i.e., early exit from generation functions),
so removing it simplifies behavior.

(Test IDLs are v. small and simple, hence often don't have
these yet, but real IDL files do.)

TBR=haraken

Review URL: https://codereview.chromium.org/145103007

git-svn-id: svn://svn.chromium.org/blink/trunk@166300 bbb929c8-8fbe-4397-9dbb-9b2b20218538