skip neon intrinsics in libpng when neon is not available

third_party/libpng/BUILD.gn

 # Copyright 2014 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/chromecast_build.gni")
+import("//build/config/arm.gni")
 
 config("libpng_config") {
   include_dirs = [ "." ]
 
   defines = []
 
   if (is_win) {
     if (is_component_build) {
       defines += [
         "PNG_USE_DLL",
@@ skipping 44 matching lines @@
   ]
 
   defines = []
 
   if (current_cpu == "x86" || current_cpu == "x64") {
     sources += [
       "contrib/intel/filter_sse2_intrinsics.c",
       "contrib/intel/intel_init.c",
     ]
     defines += [ "PNG_INTEL_SSE_OPT=1" ]
-  } else if (current_cpu == "arm" || current_cpu == "arm64") {
+  } else if ((current_cpu == "arm" || current_cpu == "arm64") && arm_use_neon) {
     sources += [
       "arm/arm_init.c",
       "arm/filter_neon_intrinsics.c",
     ]
     defines += [
       "PNG_ARM_NEON_OPT=2",
       "PNG_ARM_NEON_IMPLEMENTATION=1",
     ]
   }
 
@@ skipping 19 matching lines @@
       ":libpng_sources",
     ]
   }
 } else {
   group("libpng") {
     public_deps = [
       ":libpng_sources",
     ]
   }
 }