gn: simplify generated extensions API template.

extensions/generated_extensions_api.gni

Index: extensions/generated_extensions_api.gni
diff --git a/extensions/generated_extensions_api.gni b/extensions/generated_extensions_api.gni
index d4da603a4c019e688dec60688505b3c3b4130c8e..c8817a6d443569ecdc4bb913f04a655165ff5840 100644
--- a/extensions/generated_extensions_api.gni
+++ b/extensions/generated_extensions_api.gni
@@ -70,18 +70,9 @@ template("generated_extensions_api") {
     "$compiler_root/util_cc_helper.py",
   ]
 
-  # This list mirrors the outputs that will be generated by the following
-  # action_foreach. It's used by the static_library target.
-  compiled_schema_outputs = process_file_template(
-    schemas,
-    [ "$target_gen_dir/{{source_name_part}}.cc",
-      "$target_gen_dir/{{source_name_part}}.h",
-    ])
-
   schema_generator_name = target_name + "_schema_generator"
   action_foreach(schema_generator_name) {
     script = compiler_script
-    hard_dep = true
     source_prereqs = compiler_sources
     sources = schemas
     outputs = [
@@ -98,17 +89,15 @@ template("generated_extensions_api") {
   }
 
   bundle_generator_name = target_name + "_bundle_generator"
-  bundle_outputs = [
-    "$target_gen_dir/generated_api.cc",
-    "$target_gen_dir/generated_api.h",
-    "$target_gen_dir/generated_schemas.cc",
-    "$target_gen_dir/generated_schemas.h",
-  ]
   action(bundle_generator_name) {
     script = compiler_script
-    hard_dep = true
     source_prereqs = compiler_sources + schemas + uncompiled_schemas
-    outputs = bundle_outputs
+    outputs = [
+      "$target_gen_dir/generated_api.cc",
+      "$target_gen_dir/generated_api.h",
+      "$target_gen_dir/generated_schemas.cc",
+      "$target_gen_dir/generated_schemas.h",
+    ]
     args = [
       "--root=" + rebase_path("//", root_build_dir),
       "--destdir=" + rebase_path(root_gen_dir, root_build_dir),
@@ -121,8 +110,10 @@ template("generated_extensions_api") {
   }
 
   source_set(target_name) {
-    hard_dep = true
-    sources = compiled_schema_outputs + bundle_outputs
+    sources =
+      get_target_outputs(":$schema_generator_name") +
+      get_target_outputs(":$bundle_generator_name")
+
     deps = [
       ":$schema_generator_name",
       ":$bundle_generator_name",