libpng: Optimize RGBA png_do_expand_palette

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 = [ "." ]
 
@@ skipping 54 matching lines @@
 
   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") && arm_use_neon) {
     sources += [
       "arm/arm_init.c",
+      "arm/arm_palette.c",
       "arm/filter_neon_intrinsics.c",
     ]
     defines += [
       "PNG_ARM_NEON_OPT=2",
       "PNG_ARM_NEON_IMPLEMENTATION=1",
     ]
   }
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
@@ skipping 22 matching lines @@
       ":libpng_sources",
     ]
   }
 } else {
   group("libpng") {
     public_deps = [
       ":libpng_sources",
     ]
   }
 }