[GN] Add script to compile assets catalog without using tools/gyp.

build/toolchain/mac/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.
 
 # TODO(brettw) Use "gcc_toolchain.gni" like the Linux toolchains. This requires
 # some enhancements since the commands on Mac are slightly different than on
 # Linux.
 
 import("../goma.gni")
 import("//build/config/ios/ios_sdk.gni")
@@ skipping 226 matching lines @@
       description = copy_description
     }
 
     tool("copy_bundle_data") {
       _tool = rebase_path("//build/toolchain/mac/copy_bundle_data.py",
                           root_build_dir)
       command = "python $_tool {{source}} {{output}}"
       description = "COPY_BUNDLE_DATA {{source}} {{output}}"
     }
     tool("compile_xcassets") {
+      _tool = rebase_path("//build/toolchain/mac/compile_xcassets.py",
+                          root_build_dir)
       if (is_ios) {
-        _configuration = "Release"
-        if (is_debug) {
-          _configuration = "Debug"
-        }
+        _sdk_name = ios_sdk_name
+        _min_deployment_target = ios_deployment_target
+      } else {
+        _sdk_name = mac_sdk_name
+        _min_deployment_target = mac_deployment_target
+      }
+      command = "rm -f {{output}} && " +
+                "python $_tool -p $_sdk_name -t $_min_deployment_target " +
+                "-o {{output}} {{inputs}}"
 
-        _compile_xcassets_env =
-            "IPHONEOS_DEPLOYMENT_TARGET=$ios_deployment_target " +
-            "CONFIGURATION=$ios_sdk_name-$_configuration " +
-            "CONTENTS_FOLDER_PATH=\$(dirname {{output}})"
-      } else {
-        _compile_xcassets_env =
-            "MACOSX_DEPLOYMENT_TARGET=$mac_deployment_target " +
-            "UNLOCALIZED_RESOURCES_FOLDER_PATH=\$(dirname {{output}})"
-      }
-
-      command = "rm -f {{output}} && " +
-                "env $_compile_xcassets_env ./gyp-mac-tool compile-xcassets " +
-                "{} {{inputs}}"
       description = "COMPILE_XCASSETS {{output}}"
     }
 
     toolchain_args() {
       current_cpu = invoker.toolchain_cpu
       current_os = invoker.toolchain_os
 
       # These values need to be passed through unchanged.
       host_toolchain = host_toolchain
       target_os = target_os
@@ skipping 80 matching lines @@
 }
 
 mac_toolchain("x64") {
   toolchain_cpu = "x64"
   toolchain_os = "mac"
   cc = "${goma_prefix}/gcc"
   cxx = "${goma_prefix}/g++"
   ld = cxx
   is_clang = false
 }