Resubmit issue 2221103002 to fix the iOS build by declaring the flag in

bench/nanobench.cpp

Index: bench/nanobench.cpp
diff --git a/bench/nanobench.cpp b/bench/nanobench.cpp
index 433cfa89d9cdde2998fa3b4923ee1c2baf555631..1191423544673aef28a1a9e910a80c5185a1d24c 100644
--- a/bench/nanobench.cpp
+++ b/bench/nanobench.cpp
@@ -44,6 +44,7 @@
 #include "SkTaskGroup.h"
 #include "SkThreadUtils.h"
 #include "ThermalManager.h"
+#include "SkScan.h"
 
 #include <stdlib.h>
 
@@ -1178,6 +1179,10 @@ int nanobench_main() {
         start_keepalive();
     }
 
+    if (FLAGS_analyticAA) {
+        GlobalAAConfig::getInstance().fUseAnalyticAA = true;
+    }
+
     int runs = 0;
     BenchmarkStream benchStream;
     while (Benchmark* b = benchStream.next()) {