Revert GN declare_args() change.

tools/gn/functions_unittest.cc

 // 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.
 
 #include "tools/gn/functions.h"
 
 #include <utility>
 
 #include "base/memory/ptr_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 107 matching lines @@
   input.parsed()->Execute(setup.scope(), &err);
   ASSERT_FALSE(err.has_error()) << err.message();
 
   EXPECT_EQ(
       "empty = [[]] [[], [], []]\n"
       "one = [[1]] [[1], []]\n"
       "many = [[1, 2, 3, 4, 5], [6, 7, 8, 9]]\n"
       "rounding = [[1, 2], [3, 4], [5], [6]]\n",
       setup.print_output());
 }
-
-TEST(Functions, DeclareArgs) {
-  TestWithScope setup;
-  Err err;
-
-  // It is not legal to read the value of an argument declared in a
-  // declare_args() from inside the call, but outside the call and in
-  // a separate call should work.
-
-  TestParseInput reading_from_same_call(R"(
-      declare_args() {
-        foo = true
-        bar = foo
-      })");
-  reading_from_same_call.parsed()->Execute(setup.scope(), &err);
-  ASSERT_TRUE(err.has_error());
-
-  TestParseInput reading_from_outside_call(R"(
-      declare_args() {
-        foo = true
-      }
-
-      bar = foo
-      assert(bar)
-      )");
-  err = Err();
-  reading_from_outside_call.parsed()->Execute(setup.scope(), &err);
-  ASSERT_FALSE(err.has_error());
-
-  TestParseInput reading_from_different_call(R"(
-      declare_args() {
-        foo = true
-      }
-
-      declare_args() {
-        bar = foo
-      }
-
-      assert(bar)
-      )");
-  err = Err();
-  TestWithScope setup2;
-  reading_from_different_call.parsed()->Execute(setup2.scope(), &err);
-  ASSERT_FALSE(err.has_error());
-}