Encode all grit outputs in .gn files

build/secondary/tools/grit/grit_rule.gni

 # 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.
 
 # Instantiate grit. This will produce a script target to run grit, and a
 # static library that compiles the .cc files.
 #
 # Parameters
 #
-#   source
+#   source (required)
 #       Path to .grd file.
 #
-#   outputs (optional)
+#   outputs (required)
 #       List of outputs from grit, relative to the target_gen_dir. If supplied,
 #       a call to Grit to compute the outputs can be skipped which will make
 #       GN run faster. Grit will verify at build time that this list is correct
 #       and will fail if there is a mismatch between the outputs specified by
 #       the .grd file and the outputs list here.
 #
 #       To get this list, you can look in the .grd file for
 #       <output filename="..." and put those filename here. The base directory
 #       of the list in Grit and the output list specified in the GN grit target
 #       are the same (the target_gen_dir) so you can generally copy the names
@@ skipping 14 matching lines @@
 #   output_dir (optional)
 #     Directory for generated files.
 #
 #   deps  (optional)
 #   visibility  (optional)
 #       Normal meaning.
 #
 # Example
 #
 #   grit("my_resources") {
-#     source = "myfile.grd"  # source is required.
+#     # Source and outputs are required.
+#     source = "myfile.grd"
+#     outputs = [
+#       "foo_strings.h",
+#       "foo_strings.pak",
+#     ]
+#
 #     grit_flags = [ "-E", "foo=bar" ]  # Optional extra flags.
 #     # You can also put deps here if the grit source depends on generated
 #     # files.
 #   }
 import ("//build/config/crypto.gni")
 import ("//build/config/features.gni")
 import ("//build/config/ui.gni")
 
 grit_defines = []
 
@@ skipping 146 matching lines @@
 
   if (defined(invoker.grit_flags)) {
     grit_flags = invoker.grit_flags
   } else {
     grit_flags = []  # These are optional so default to empty list.
   }
 
   grit_inputs = [ invoker.source ]
 
   assert_files_flags = []
-  if (defined(invoker.outputs)) {
-    # If the declaration specified outputs, we want to make sure that they
-    # actually match what Grit is writing. We write the list to a file (some
-    # of the output lists are long enough to not fit on a Windows command line)
-    # and ask Grit to verify those are the actual outputs at runtime.
-    asserted_list_file = "$target_out_dir/${target_name}_expected_outputs.txt"
-    write_file(asserted_list_file,
-               rebase_path(invoker.outputs, root_build_dir, target_gen_dir))
-    assert_files_flags += [
-      "--assert-file-list=" + rebase_path(asserted_list_file, root_build_dir),
-    ]
-    grit_outputs = get_path_info(
-        rebase_path(invoker.outputs, ".", target_gen_dir),
-        "abspath")
-  } else {
-    # Ask Grit for the output list.
-    grit_outputs_build_rel = exec_script(grit_info_script,
-      [ "--outputs", "$rebased_output_dir", source_path, "-f", resource_ids ] +
-      grit_flags,
-      "list lines")
 
-    # The names returned by grit are relative to the current (build) directory,
-    # but references to files in this template are expected to be relative to
-    # the invoking BUILD.gn file's directory. Make it absolute so there's no
-    # ambiguity.
-    grit_outputs = get_path_info(
-        rebase_path(grit_outputs_build_rel, ".", root_build_dir), "abspath")
-  }
+  # We want to make sure the declared outputs actually match what Grit is
+  # writing. We write the list to a file (some of the output lists are long
+  # enough to not fit on a Windows command line) and ask Grit to verify those
+  # are the actual outputs at runtime.
+  asserted_list_file = "$target_out_dir/${target_name}_expected_outputs.txt"
+  write_file(asserted_list_file,
+             rebase_path(invoker.outputs, root_build_dir, target_gen_dir))
+  assert_files_flags += [
+    "--assert-file-list=" + rebase_path(asserted_list_file, root_build_dir),
+  ]
+  grit_outputs = get_path_info(
+      rebase_path(invoker.outputs, ".", target_gen_dir),
+      "abspath")
 
   # The config and the action below get this visibility son only the generated
   # source set can depend on them. The variable "target_name" will get
   # overwritten inside the innter classes so we need to compute it here.
   target_visibility = ":$target_name"
 
   # The current grit setup makes an file in $output_dir/grit/foo.h that
   # the source code expects to include via "grit/foo.h". It would be nice to
   # change this to including absolute paths relative to the root gen directory
   # (like "mycomponent/foo.h"). This config sets up the include path.
@@ skipping 39 matching lines @@
     direct_dependent_configs = [ ":$grit_config" ]
 
     if (defined(invoker.visibility)) {
       visibility = invoker.visibility
     }
     if (defined(invoker.output_name)) {
       output_name = invoker.output_name
     }
   }
 }