Ignore arm_neon_optional if arm_neon==1 in skia.

skia/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
@@ skipping 184 matching lines @@
 
   defines = []
 
   if (component_mode == "shared_library") {
     defines += [ "SKIA_IMPLEMENTATION=1" ]
   }
 
   if (current_cpu == "arm") {
     if (arm_use_neon) {
       defines += [ "SK_ARM_HAS_NEON" ]
-    }
-    if (arm_optionally_use_neon) {
+    } else if (arm_optionally_use_neon) {
       defines += [ "SK_ARM_HAS_OPTIONAL_NEON" ]
     }
   }
 
   # Settings for text blitting, chosen to approximate the system browser.
   if (is_linux) {
     defines += [
       "SK_GAMMA_EXPONENT=1.2",
       "SK_GAMMA_CONTRAST=0.2",
       "SK_HIGH_QUALITY_IS_LANCZOS",
@@ skipping 453 matching lines @@
       "tools/filter_fuzz_stub/filter_fuzz_stub.cc",
     ]
 
     deps = [
       ":skia",
       "//base",
       "//base/test:test_support",
     ]
   }
 }