Add lots of GN targets

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 c8817a6d443569ecdc4bb913f04a655165ff5840..e231157e65f35052f4878d1f97fda57a5055aa7e 100644
--- a/extensions/generated_extensions_api.gni
+++ b/extensions/generated_extensions_api.gni
@@ -11,20 +11,27 @@
 #
 # sources [required] A list of schema files to be compiled.
 #
-# root_namespace [required] The namespace in which generated API code is to be
+# root_namespace [required]
+#   The namespace in which generated API code is to be
 #   wrapped. C++ namespace syntax is accepted for nested namespace
 #   (e.g. "foo::bar::api").
 #
-# impl_dir [required] The path containing C++ implementations of API functions.
-#   This path is used as the root path when looking for
-#   {schema}/{schema}_api.h headers during the API bundle generation phase.
-#   Such headers, if found, are automatically included by the generated code.
+# bundle [optional, default = false]
+#   Boolean indicating if the schema files should be bundled or not.
 #
-# uncompiled_sources [optional] A list of schema files which should not be
-#   compiled, but which should still be processed for API bundle generation.
+# impl_dir [required if bundle = true, otherwise unused]
+#   The path containing C++ implementations of API functions. This path is
+#   used as the root path when looking for {schema}/{schema}_api.h headers
+#   during the API bundle generation phase. Such headers, if found, are
+#   automatically included by the generated code.
 #
-# deps [optional] If any deps are specified they will be inherited by the
-#   static library target.
+# uncompiled_sources [optional, only used when bundle = true]
+#   A list of schema files which should not be compiled, but which should still
+#   be processed for API bundle generation.
+#
+# deps [optional]
+#   If any deps are specified they will be inherited by the static library
+#   target.
 #
 # The static libarary target also inherits the visibility and output_name
 # of its invoker.
@@ -34,8 +41,8 @@ template("generated_extensions_api") {
          "\"sources\" must be defined for the $target_name template.")
   assert(defined(invoker.root_namespace),
          "\"root_namespace\" must be defined for the $target_name template.")
-  assert(defined(invoker.impl_dir),
-         "\"impl_dir\" must be defined for the $target_name template.")
+
+  bundle = defined(invoker.bundle) && invoker.bundle
 
   # Keep a copy of the target_name here since it will be trampled
   # in nested targets.
@@ -49,11 +56,6 @@ template("generated_extensions_api") {
 
   schemas = invoker.sources
   root_namespace = invoker.root_namespace
-  impl_dir = invoker.impl_dir
-  uncompiled_schemas = []
-  if (defined(invoker.uncompiled_sources)) {
-    uncompiled_schemas = invoker.uncompiled_sources
-  }
 
   compiler_root = "//tools/json_schema_compiler"
   compiler_script = "$compiler_root/compiler.py"
@@ -88,38 +90,51 @@ template("generated_extensions_api") {
     visibility = target_visibility
   }
 
-  bundle_generator_name = target_name + "_bundle_generator"
-  action(bundle_generator_name) {
-    script = compiler_script
-    source_prereqs = compiler_sources + schemas + uncompiled_schemas
-    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),
-      "--namespace=$root_namespace",
-      "--generator=cpp-bundle",
-      "--impl-dir=" + rebase_path(impl_dir, "//"),
-    ] +
-      rebase_path(schemas, root_build_dir) +
-      rebase_path(uncompiled_schemas, root_build_dir)
+  if (bundle) {
+    assert(defined(invoker.impl_dir),
+           "\"impl_dir\" must be defined for the $target_name template.")
+    impl_dir = invoker.impl_dir
+
+    uncompiled_schemas = []
+    if (defined(invoker.uncompiled_sources)) {
+      uncompiled_schemas = invoker.uncompiled_sources
+    }
+
+    bundle_generator_name = target_name + "_bundle_generator"
+    action(bundle_generator_name) {
+      script = compiler_script
+      source_prereqs = compiler_sources + schemas + uncompiled_schemas
+      outputs = [
+        "$target_gen_dir/generated_api.cc",
+        "$target_gen_dir/generated_api.h",
+        "$target_gen_dir/generated_schemas.cc",
+        "$target_gen_dir/generated_schemas.h",
+      ]
+      args = [
+        "--root=" + rebase_path("//", root_build_dir),
+        "--destdir=" + rebase_path(root_gen_dir, root_build_dir),
+        "--namespace=$root_namespace",
+        "--generator=cpp-bundle",
+        "--impl-dir=" + rebase_path(impl_dir, "//"),
+      ] +
+        rebase_path(schemas, root_build_dir) +
+        rebase_path(uncompiled_schemas, root_build_dir)
+    }
   }
 
   source_set(target_name) {
-    sources =
-      get_target_outputs(":$schema_generator_name") +
-      get_target_outputs(":$bundle_generator_name")
+    sources = get_target_outputs(":$schema_generator_name")
 
     deps = [
       ":$schema_generator_name",
-      ":$bundle_generator_name",
       "//tools/json_schema_compiler:generated_api_util",
     ]
 
+    if (bundle) {
+      sources += get_target_outputs(":$bundle_generator_name")
+      deps += [ ":$bundle_generator_name" ]
+    }
+
     if (defined(invoker.deps)) {
       deps += invoker.deps
     }