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>
diff --git a/src/gpu/ops/GrSmallPathRenderer.cpp b/src/gpu/ops/GrSmallPathRenderer.cpp
index fd868a1..222f662 100644
--- a/src/gpu/ops/GrSmallPathRenderer.cpp
+++ b/src/gpu/ops/GrSmallPathRenderer.cpp
@@ -455,7 +455,7 @@
                                                   devPathBounds.height()))) {
                 return false;
             }
-            sk_bzero(dst.writable_addr(), dst.getSafeSize());
+            sk_bzero(dst.writable_addr(), dst.computeByteSize());
 
             // rasterize path
             SkPaint paint;
@@ -562,7 +562,7 @@
                                               devPathBounds.height()))) {
             return false;
         }
-        sk_bzero(dst.writable_addr(), dst.getSafeSize());
+        sk_bzero(dst.writable_addr(), dst.computeByteSize());
 
         // rasterize path
         SkPaint paint;