Remove SK_SUPPORT_LEGACY_RECT flag

The rebaseline has finished in Chromium.

Bug: skia:
Change-Id: Ibafb32b3683f1bfc3e451911e6fb8382bfc9b857
Reviewed-on: https://skia-review.googlesource.com/23481
Reviewed-by: Cary Clark <caryclark@google.com>
Commit-Queue: Yuqian Li <liyuqian@google.com>
diff --git a/src/core/SkScan_AntiPath.cpp b/src/core/SkScan_AntiPath.cpp
index 093de43..69b5ba1 100644
--- a/src/core/SkScan_AntiPath.cpp
+++ b/src/core/SkScan_AntiPath.cpp
@@ -638,11 +638,9 @@
     if (gSkForceAnalyticAA.load()) {
         return true;
     }
-#ifndef SK_SUPPORT_LEGACY_RECT
     if (path.isRect(nullptr)) {
         return true;
     }
-#endif
     const SkRect& bounds = path.getBounds();
     // When the path have so many points compared to the size of its bounds/resolution,
     // it indicates that the path is not quite smooth in the current resolution: