GN: Avoid failing unconditionally on iOS due to the lack of a target for icudata

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("//third_party/icu/config.gni")
 
 # Meta target that includes both icuuc and icui18n. Most targets want both.
 # You can depend on the individually if you need to.
 group("icu") {
   deps = [
@@ skipping 485 matching lines @@
 
   if (is_win || icu_use_data_file) {
     sources += [ "source/stubdata/stubdata.c" ]
     defines += [ "U_ICUDATAENTRY_IN_COMMON" ]
   }
 }
 
 # TODO(GYP) support use_system_icu.
 if (icu_use_data_file) {
   if (is_ios) {
-    # TODO(GYP): Support mac resource bundle shown below.
-    # 'link_settings': {
-    #   'mac_bundle_resources': [
-    #     'source/data/in/icudtl.dat',
-    #   ],
-    # }
+    group("icudata") {
+      # TODO(csg): Provide an empty group so that this target does not
+      # unconditionally fail. The dat file needs to be bundled separately. In
+      # the longer term, need to figure out how to use system ICU
+    }

[Dirk Pranke, 2015/06/16 00:46:41]

Please leave this as TODO(GYP): so that we can track all of the
transition-related things more easily. If you want to also have TODO(csg), feel
free to list both.

   } else {
     copy("icudata") {
       if (is_android) {
         sources = [
           "android/icudtl.dat",
         ]
       } else {
         sources = [
           "source/data/in/icudtl.dat",
         ]
@@ skipping 41 matching lines @@
         sources = [
           "android/icudtl_dat.S",
         ]
       } else {
         assert(false, "No icu data for this platform")
       }
       defines = [ "U_HIDE_DATA_SYMBOL" ]
     }
   }
 }