Wire ServiceWorker protocol interceptor

Also adds implementation for FALLBACK_TO_NETWORK case in
ServiceWorkerURLRequest, so that launching chrome with
--enable-service-worker doesn't block every resource request.

BUG=349319

Review URL: https://codereview.chromium.org/196793003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256790 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256790
Fix mojo_js_unittests

BUG=351214
TEST=The test should succeed

Review URL: https://codereview.chromium.org/197463005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256791 0039d316-1c4b-4281-b951-d872f2087c98
Support unions in extensions IDl dictionaries.

This change adds support for unions in extensions IDL dictionaries, such
as the following:

dictionary foo {
  (long or DOMString) bar;
};

Unions are also supported in callback and function parameters.

NOTRY=true
BUG=339558

Review URL: https://codereview.chromium.org/181143002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256792 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256792