IDL compiler: compute dependencies for generated IDL files

This CL makes the Python build work!
(Previously failed on generated IDL files, used in testing.)


Currently generated IDL files are not fed into compute_dependencies.py.

This causes problems for the Python build, since Python requires that
dependencies are calculated through this script (Perl just reads files
whenever it feels like), and it's also requires special-casing the
"constructors on global objects" IDL files, making the build more complicated.

This fixes it by passing generated files into compute_dependencies.
The one twist is that generated files have to be passed *on the command line*,
instead of in a generated list file (which we use for the 600+ static IDL
files).
This is b/c generated files are in the build dir, and this is only known at
*build* time (for some build systems), while the GYP variable that generates
the temporary list file (the "<|(...)" rule) runs at *gyp* time.
(This is why there used to be an --additionalIdlFiles command line parameter;
 we don't need that for the original purpose, but we do need it here.)

To make this clear, I distinguish *static* and *generated* IDL files in
the .gyp file.
Thus we distinguish interface/dependency and static/generated in one place,
and the actual actions and rules have simple inputs.

This also requires adding [NoInterfaceObject] to the testing IDL files,
which they actually needed all along, but were skipped b/c they were
being handled separately.

Also:
* some formatting fixes,
* remove unused GYP options (for cc, which isn't used here), and
* update the list of Python files.

Background:
This "generated files in gyp-time generated file <|(...)" problem
originally arose back in 2012, and resulted in the
--additionalIdlFiles flag for the Perl compiler:
Bug 104831 - [chromium] don't write additional idl files to a gyp temp file
https://bugs.webkit.org/show_bug.cgi?id=104831

I got rid off this flag from the Python compiler
b/c it's not needed by the *compiler*:
Split dependencies from built IDL files in GYP
https://codereview.chromium.org/136033011/
...but it is needed by *dependency resolution*,
which is why I'm adding it back.
This time I'm passing the files as command line arguments,
not a string, hence we don't need to do any string parsing/unpacking,
which makes the code v. simple.

BUG=239771
BUG=341748
R=haraken

Review URL: https://codereview.chromium.org/166133002

git-svn-id: svn://svn.chromium.org/blink/trunk@167177 bbb929c8-8fbe-4397-9dbb-9b2b20218538