Revert "remove SkCanvas::kIsOpaque_SaveLayerFlag"

This reverts commit 9a7a2ee5ad8453a985d7d76c1e0ebb50d17fec63.

Reason for revert: still need to update blink_headless in Google3

Original change's description:
> remove SkCanvas::kIsOpaque_SaveLayerFlag
> 
> This is a performance-only hint that no one but fuzzers
> is using.  It's even explicitly filtered out in Android.
> 
> The fuzzers have noticed they can trick us into allocating
> uninitialized memory and treating it as opaque, blending
> uninitialized pixels, etc.
> 
> Since no one's using this, we can just kill the bit.
> 
> Bug: skia:7566, chromium:808830
> 
> Change-Id: Id74a85e51bc4d0907b4127eb9ac5b02576f8f0a7
> Reviewed-on: https://skia-review.googlesource.com/104441
> Reviewed-by: Mike Reed <reed@google.com>
> Commit-Queue: Mike Klein <mtklein@chromium.org>

TBR=mtklein@chromium.org,fmalita@chromium.org,reed@google.com

Change-Id: I10d3c7e5184b9322715a5bfb6a7106292c8876a3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:7566, chromium:808830
Reviewed-on: https://skia-review.googlesource.com/104781
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fuzz/FuzzCanvas.cpp b/fuzz/FuzzCanvas.cpp
index ffc8781e6b..0334d85d36 100644
--- a/fuzz/FuzzCanvas.cpp
+++ b/fuzz/FuzzCanvas.cpp
@@ -1150,6 +1150,9 @@ static void fuzz_canvas(Fuzz* fuzz, SkCanvas* canvas, int depth = 9) {
                 }
                 // _DumpCanvas can't handle this.
                 // if (make_fuzz_t<bool>(fuzz)) {
+                //     saveLayerRec.fSaveLayerFlags |= SkCanvas::kIsOpaque_SaveLayerFlag;
+                // }
+                // if (make_fuzz_t<bool>(fuzz)) {
                 //     saveLayerRec.fSaveLayerFlags |= SkCanvas::kPreserveLCDText_SaveLayerFlag;
                 // }