Revert "Initialize buffer contents separately from BufferImpl::setData" This reverts commit 34cff1a14b635c76a9063b8710e948d04ef98a79. Reason for revert: Speculative revert for Mac M1 WebGL failures. Bug: chromium:1330314 Original change's description: > Initialize buffer contents separately from BufferImpl::setData > > Some backends can initialize buffer data faster than allocating a > zero-filled scratch buffer (GL can map and memset for example). > Allow those backends the opportunity to make these optimizations. > > Verified that GL, D3D and VK backends do not regress by using a > separate set data call. > > Bug: chromium:983167 > Change-Id: Ibcbe6016059434dc36ab3c754df6a24f0a6e5e72 > Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3039778 > Reviewed-by: Jamie Madill <jmadill@chromium.org> > Reviewed-by: Peng Huang <penghuang@chromium.org> > Commit-Queue: Geoff Lang <geofflang@chromium.org> Bug: chromium:983167 Change-Id: Id1bfa76b832c35fd0b3ade04da16735aa089fdd2 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3677335 Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com> Commit-Queue: Peng Huang <penghuang@chromium.org>