Enforce 16byte alignment in shader contexts (patchset #1 id:1 of https://codereview.chromium.org/1759653004/ )"

This reverts commit e38bcaf24b00066e167e03a5ac63cf828914d747.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1763973002

TBR=

Review URL: https://codereview.chromium.org/1763973002
30 files changed