Added ISwapChainPanel support

Change-Id: I26faa32804ee47cb6ad8458c90abeb93a01dfbdf
Reviewed-on: https://chromium-review.googlesource.com/224991
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
Fix an incorrect iteration over EGL attributes.

BUG=angle:490

Change-Id: If7a86ee0a5226f2b45e26bbadf4a84f8f605d1c2
Reviewed-on: https://chromium-review.googlesource.com/227231
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>