Change FLAGS_analyticAA's default to true

BUG=skia:

Change-Id: I1abf2284ed9dfaa69110c4fe86325c8e4ee43317
Reviewed-on: https://skia-review.googlesource.com/5767
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Yuqian Li <liyuqian@google.com>
diff --git a/dm/DM.cpp b/dm/DM.cpp
index ce45515..021b411 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -1296,9 +1296,7 @@
     setbuf(stdout, nullptr);
     setup_crash_handler();
 
-    if (FLAGS_analyticAA) {
-        gSkUseAnalyticAA = true;
-    }
+    gSkUseAnalyticAA = FLAGS_analyticAA;
 
     if (FLAGS_verbose) {
         gVLog = stderr;