guard old apis for querying byte-size of a bitmap/imageinfo/pixmap

Now with legacy behavior for allocpixels

This was reverted, so the current CL is a "fix" on top of ...
https://skia-review.googlesource.com/c/skia/+/50980

Related update to Chrome (in preparation for this change)
https://chromium-review.googlesource.com/c/chromium/src/+/685719

Bug: skia:
Change-Id: I4b370ee7e95083ab27421f008132219c9c7b86e9
Reviewed-on: https://skia-review.googlesource.com/51341
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
41 files changed