Check for inputs not generated by deps

tools/gn/function_write_file_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 "base/files/file.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/functions.h"
+#include "tools/gn/scheduler.h"
 #include "tools/gn/test_with_scope.h"
 
 namespace {
 
 // Returns true on success, false if write_file signaled an error.
 bool CallWriteFile(Scope* scope,
                    const std::string& filename,
                    const Value& data) {
   Err err;
 
   std::vector<Value> args;
   args.push_back(Value(nullptr, filename));
   args.push_back(data);
 
   FunctionCallNode function_call;
   Value result = functions::RunWriteFile(scope, &function_call, args, &err);
   EXPECT_EQ(Value::NONE, result.type());  // Should always return none.
 
   return !err.has_error();
 }
 
 }  // namespace
 
 TEST(WriteFile, WithData) {
+  Scheduler scheduler;
   TestWithScope setup;
 
   // Make a real directory for writing the files.
   base::ScopedTempDir temp_dir;
   ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
   setup.build_settings()->SetRootPath(temp_dir.path());
   setup.build_settings()->SetBuildDir(SourceDir("//out/"));
 
   Value some_string(nullptr, "some string contents");
 
@@ skipping 33 matching lines @@
   base::File::Info original_info;
   foo_file.GetInfo(&original_info);
 
   EXPECT_TRUE(CallWriteFile(setup.scope(), "//out/foo.txt", some_list));
 
   // Verify that the last modified time is the same as before.
   base::File::Info new_info;
   foo_file.GetInfo(&new_info);
   EXPECT_EQ(original_info.last_modified, new_info.last_modified);
 }