Add option for fuzzer to toggle DAA

Of note, this is a breaking change to the fuzzed format
for any canvas fuzzers.  I've updated the seed corpora to match
but any repro cases predating this will need to have the a single
byte added to the front of the test case:

echo -n -e '\x00' | cat - file > outputfile


Bug: 847386
Change-Id: I10b3b228e9c121340857fb8e7807464e54e9238a
Reviewed-on: https://skia-review.googlesource.com/131522
Auto-Submit: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Yuqian Li <liyuqian@google.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/fuzz/FuzzCanvas.cpp b/fuzz/FuzzCanvas.cpp
index b843804460..8e84e88b3c 100644
--- a/fuzz/FuzzCanvas.cpp
+++ b/fuzz/FuzzCanvas.cpp
@@ -1077,11 +1077,20 @@ static sk_sp<SkTextBlob> make_fuzz_textblob(Fuzz* fuzz) {
     return textBlobBuilder.make();
 }
 
+extern std::atomic<bool> gSkUseDeltaAA;
+extern std::atomic<bool> gSkForceDeltaAA;
+
 static void fuzz_canvas(Fuzz* fuzz, SkCanvas* canvas, int depth = 9) {
     if (!fuzz || !canvas || depth <= 0) {
         return;
     }
     SkAutoCanvasRestore autoCanvasRestore(canvas, false);
+    bool useDAA;
+    fuzz->next(&useDAA);
+    if (useDAA) {
+        gSkForceDeltaAA = true;
+        gSkUseDeltaAA = true;
+    }
     unsigned N;
     fuzz->nextRange(&N, 0, 2000);
     for (unsigned i = 0; i < N; ++i) {