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

dm/DM.cpp

Index: dm/DM.cpp
diff --git a/dm/DM.cpp b/dm/DM.cpp
index 53709ba76dab27691441643227d65a56285379ac..c6e2ab98c71cbfd792baaa4bc0ca508f01d06270 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -34,6 +34,7 @@
 #include "Timer.h"
 #include "picture_utils.h"
 #include "sk_tool_utils.h"
+#include "SkScan.h"
 
 #ifdef SK_PDF_IMAGE_STATS
 extern void SkPDFImageDumpStats();
@@ -1274,6 +1275,10 @@ int dm_main() {
     setbuf(stdout, nullptr);
     setup_crash_handler();
 
+    if (FLAGS_analyticAA) {
+        GlobalAAConfig::getInstance().fUseAnalyticAA = true;
+    }
+
     if (FLAGS_verbose) {
         gVLog = stderr;
     } else if (!FLAGS_writePath.isEmpty()) {