Revert of Allow NEON on iOS.

include/core/SkPreConfig.h

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPreConfig_DEFINED
@@ skipping 180 matching lines @@
         #endif
     #endif
 #endif
 
 // Disable ARM64 optimizations for iOS due to complications regarding gyp and iOS.
 #if defined(__aarch64__) && !defined(SK_BUILD_FOR_IOS)
     #define SK_CPU_ARM64
 #endif
 
 // All 64-bit ARM chips have NEON.  Many 32-bit ARM chips do too.
-#if !defined(SK_ARM_HAS_NEON) && (defined(SK_CPU_ARM64) || defined(__ARM_NEON__))
+// TODO: Why don't we want NEON on iOS?
+#if !defined(SK_ARM_HAS_NEON) && !defined(SK_BUILD_FOR_IOS) && \
+    (defined(SK_CPU_ARM64) || defined(__ARM_NEON__))
     #define SK_ARM_HAS_NEON
 #endif
 
 //////////////////////////////////////////////////////////////////////
 
 #if !defined(SKIA_IMPLEMENTATION)
     #define SKIA_IMPLEMENTATION 0
 #endif
 
 #if defined(SKIA_DLL)
@@ skipping 48 matching lines @@
  *
  * NOTE: Clang/ARM (r161757) does not support the 'optimize' attribute.
  */
 #if SK_HAS_ATTRIBUTE(optimize)
 #   define SK_ATTRIBUTE_OPTIMIZE_O1 __attribute__((optimize("O1")))
 #else
 #   define SK_ATTRIBUTE_OPTIMIZE_O1 /* nothing */
 #endif
 
 #endif