Support WebGL 1.0 with caps

There is some logic in here for 2.0 as well, just as a
"as long as I was looking at the specs", but only 1.0
is really supported.

This seems to resolve the bug where some GPUs weren't
advertising correctly that they had vertex array object
support, by checking for both extension names (with and
without "GL_" prefix)

Of note, this saves about 18 Kb (5.5 Kb gzipped) of code size
by compiling out the unneeded GLES checks/functionality.

Bug: skia:8378
Change-Id: I773bf4dbf231b991051d2a9f640b8047a9010e7d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/203461
Commit-Queue: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
20 files changed