Pass the bundle product_type to the actool invocation.

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/clang/clang.gni")
@@ skipping 388 matching lines @@
       if (is_ios) {
         _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}} && " +
                 "TOOL_VERSION=${tool_versions.compile_xcassets} " +
                 "python $_tool -p $_sdk_name -t $_min_deployment_target " +
-                "-o {{output}} {{inputs}}"
+                "-T {{bundle_product_type}} -o {{output}} {{inputs}}"
 
       description = "COMPILE_XCASSETS {{output}}"
       pool = ":bundle_pool($default_toolchain)"
     }
   }
 }
 
 mac_toolchain("clang_arm") {
   toolchain_args = {
     current_cpu = "arm"
@@ skipping 30 matching lines @@
     }
   }
 
   mac_toolchain("ios_clang_x64") {
     toolchain_args = {
       current_cpu = "x64"
       current_os = "ios"
     }
   }
 }