Further reduce google3 stack size

It seems that the compiler added the stack size of two "if" branches,
rather than get the max of them...

Bug: skia:
Change-Id: Idf6b47cafd84c9a53a7b8dafb38f815e08094100
Reviewed-on: https://skia-review.googlesource.com/26780
Reviewed-by: Yuqian Li <liyuqian@google.com>
Commit-Queue: Yuqian Li <liyuqian@google.com>
diff --git a/src/core/SkCoverageDelta.h b/src/core/SkCoverageDelta.h
index bf0baf2..d12e006 100644
--- a/src/core/SkCoverageDelta.h
+++ b/src/core/SkCoverageDelta.h
@@ -121,7 +121,11 @@
 
     static constexpr int SIMD_WIDTH     = 8;
     static constexpr int SUITABLE_WIDTH = 32;
+#ifndef GOOGLE3
     static constexpr int MAX_MASK_SIZE  = 2048;
+#else
+    static constexpr int MAX_MASK_SIZE  = 1024;
+#endif
 
     // Expand PADDING on both sides, and make it a multiple of SIMD_WIDTH
     static int  ExpandWidth(int width);