Update GN toolchain_args to be a variable.

tools/gn/function_forward_variables_from_unittest.cc

 // Copyright 2015 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.
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/scheduler.h"
 #include "tools/gn/test_with_scope.h"
 
 TEST(FunctionForwardVariablesFrom, List) {
   Scheduler scheduler;
@@ skipping 32 matching lines @@
     // variable in the scope before it.
     TestParseInput clobber("x = 1\n" + program);
     ASSERT_FALSE(clobber.has_error());
 
     clobber.parsed()->Execute(setup.scope(), &err);
     ASSERT_TRUE(err.has_error());  // Should thow a clobber error.
     EXPECT_EQ("Clobbering existing value.", err.message());
   }
 }
 
+TEST(FunctionForwardVariablesFrom, LiteralList) {
+  Scheduler scheduler;
+  TestWithScope setup;
+
+  // Forwards all variables from a literal scope into another scope definition.
+  TestParseInput input(
+    "a = {\n"
+    "  forward_variables_from({x = 1 y = 2}, \"*\")\n"
+    "  z = 3\n"
+    "}\n"
+    "print(\"${a.x} ${a.y} ${a.z}\")\n");
+
+  ASSERT_FALSE(input.has_error());
+
+  Err err;
+  input.parsed()->Execute(setup.scope(), &err);
+  ASSERT_FALSE(err.has_error()) << err.message();
+
+  EXPECT_EQ("1 2 3\n", setup.print_output());
+  setup.print_output().clear();
+}
+
 TEST(FunctionForwardVariablesFrom, ListWithExclusion) {
   Scheduler scheduler;
   TestWithScope setup;
 
   // Defines a template and copy the two x and y, and z values out.
   TestParseInput input(
     "template(\"a\") {\n"
     "  forward_variables_from(invoker, [\"x\", \"y\", \"z\"], [\"z\"])\n"
     "  assert(!defined(z))\n"  // "z" should still be undefined.
     "  print(\"$target_name, $x, $y\")\n"
@@ skipping 24 matching lines @@
     "template(\"a\") {\n"
     "  forward_variables_from(42, [\"x\"])\n"
     "  print(\"$target_name\")\n"  // Prevent unused var error.
     "}\n"
     "a(\"target\") {\n"
     "}\n");
   ASSERT_FALSE(invalid_source.has_error());
   Err err;
   invalid_source.parsed()->Execute(setup.scope(), &err);
   EXPECT_TRUE(err.has_error());
-  EXPECT_EQ("Expected an identifier for the scope.", err.message());
+  EXPECT_EQ("This is not a scope.", err.message());
 
   // Type check the list. We need to use a new template name each time since
   // all of these invocations are executing in sequence in the same scope.
   TestParseInput invalid_list(
     "template(\"b\") {\n"
     "  forward_variables_from(invoker, 42)\n"
     "  print(\"$target_name\")\n"
     "}\n"
     "b(\"target\") {\n"
     "}\n");
@@ skipping 109 matching lines @@
 
   ASSERT_FALSE(input.has_error());
 
   Err err;
   input.parsed()->Execute(setup.scope(), &err);
   ASSERT_FALSE(err.has_error()) << err.message();
 
   EXPECT_EQ("3\ntarget, 1, 2\n", setup.print_output());
   setup.print_output().clear();
 }