Based on https://github.com/google/skia/commit/b79ff56de23fef680ae7187040f2d6a9516b553d

Index: mozilla-release/gfx/skia/trunk/src/core/SkUtilsArm.h
===================================================================
--- mozilla-release.orig/gfx/skia/trunk/src/core/SkUtilsArm.h
+++ mozilla-release/gfx/skia/trunk/src/core/SkUtilsArm.h
@@ -21,9 +21,9 @@
 #define SK_ARM_NEON_MODE_ALWAYS   1
 #define SK_ARM_NEON_MODE_DYNAMIC  2
 
-#if defined(SK_CPU_ARM32) && defined(__ARM_HAVE_OPTIONAL_NEON_SUPPORT)
+#if defined(__ARM_HAVE_OPTIONAL_NEON_SUPPORT)
 #  define SK_ARM_NEON_MODE  SK_ARM_NEON_MODE_DYNAMIC
-#elif defined(SK_CPU_ARM32) && defined(__ARM_HAVE_NEON) || defined(SK_CPU_ARM64)
+#elif defined(__ARM_HAVE_NEON)
 #  define SK_ARM_NEON_MODE  SK_ARM_NEON_MODE_ALWAYS
 #else
 #  define SK_ARM_NEON_MODE  SK_ARM_NEON_MODE_NONE