ServiceWorker: Change worker script fetch error code.

Change layout test error code, add worker script redirect test.

(1/3): https://codereview.chromium.org/546353003/
(2/3): https://codereview.chromium.org/567903002/
(3/3): this

BUG=408421
TEST=http/tests/serviceworker

Review URL: https://codereview.chromium.org/597483002

git-svn-id: svn://svn.chromium.org/blink/trunk@182570 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Update expectations for flaky tiled-layer-recursion test.

Because flaky after

https://codereview.chromium.org/567743003

TBR=sky@chromium.org
NOTRY=true
BUG=417174

Review URL: https://codereview.chromium.org/595243002

git-svn-id: svn://svn.chromium.org/blink/trunk@182571 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Update test expectations with XHR test that has become flaky after recent changes.

TBR=kouhei@chromium.org
NOTRY=true
BUG=417181

Review URL: https://codereview.chromium.org/593383004

git-svn-id: svn://svn.chromium.org/blink/trunk@182572 bbb929c8-8fbe-4397-9dbb-9b2b20218538
bindings: Support sequence<sequence<T>> in method arguments

modules/serviceworkers/Headers.idl depends on generic Dictionary
because the IDL compiler doesn't support sequence<sequence<T>>.
Support it to remove this dependency.

Review URL: https://codereview.chromium.org/597053002

git-svn-id: svn://svn.chromium.org/blink/trunk@182573 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Mark compositing tests for rebaselining on Mac after TiledLayer change.

TBR=sky@chromium.org
NOTRY=true
BUG=417182

Review URL: https://codereview.chromium.org/598493004

git-svn-id: svn://svn.chromium.org/blink/trunk@182574 bbb929c8-8fbe-4397-9dbb-9b2b20218538