IDL build: Split global object computation into core and modules

This completes the split!

Note that this deletes the top-level:
* bindings/generated.gypi
* bindings/idl.gypi
...and eliminates the variable bindings_output_dir, b/c we do not output
anything to there any longer!

One layering violation is:
constructors for interfaces in core need to know about
global objects defined in modules,
namely ServiceWorker, because some of these are exposed
to ServiceWorker.

This can be fixed by moving
ServiceWorkerGlobalScopeCoreConstructors.idl
to modules, which I'll do in a followup.

R=haraken
BUG=358074

Review URL: https://codereview.chromium.org/315003004

git-svn-id: svn://svn.chromium.org/blink/trunk@175554 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove scoped styles.

Removes <style scoped>.

This was discussed and approved with LGTMs in blink-dev:
https://groups.google.com/a/chromium.org/d/msg/blink-dev/R1x18ZLS5qQ/Bjuh_cENhlQJ

Chrome status dashboard entry:
http://www.chromestatus.com/features/5374137958662144

Note:
this is based on esprehn's original cl:
https://codereview.chromium.org/214693002/

BUG=379096
TEST=pass all layout tests

Review URL: https://codereview.chromium.org/310443002

git-svn-id: svn://svn.chromium.org/blink/trunk@175555 bbb929c8-8fbe-4397-9dbb-9b2b20218538