Bump hardware decoding limits to 4k.
Bump hardware decoding limits to 4k.

Devices like the S6+ can decode 4k content. If a device fails to
configure we'll just fallback to software anyways.

BUG=610892
TEST=samsung s6 plays hardware vp8/vp9

Review-Url: https://codereview.chromium.org/1963413002
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#392805}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk