Check for GN args using the union of all rather than individually.

tools/gn/setup.h

 // Copyright (c) 2013 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.
 
 #ifndef TOOLS_GN_SETUP_H_
 #define TOOLS_GN_SETUP_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 21 matching lines @@
   virtual ~CommonSetup();
 
   // Returns the scheduler. This is virtual since only the main setup has a
   // scheduler and the derived ones just store pointers.
   virtual Scheduler* GetScheduler() = 0;
 
   // When true (the default), Run() will check for unresolved dependencies and
   // cycles upon completion. When false, such errors will be ignored.
   void set_check_for_bad_items(bool s) { check_for_bad_items_ = s; }
 
+  // When true (the default), RunPostMessageLoop will check for overrides that
+  // were specified but not used. When false, such errors will be ignored.
+  void set_check_for_unused_overrides(bool s) {
+    check_for_unused_overrides_ = s;
+  }
+
   BuildSettings& build_settings() { return build_settings_; }
   Builder* builder() { return builder_.get(); }
   LoaderImpl* loader() { return loader_.get(); }
 
  protected:
   CommonSetup();
   CommonSetup(const CommonSetup& other);
 
   // Performs the two sets of operations to run the generation before and after
   // the message loop is run.
   void RunPreMessageLoop();
   bool RunPostMessageLoop();
 
   BuildSettings build_settings_;
   scoped_refptr<LoaderImpl> loader_;
   scoped_refptr<Builder> builder_;
 
   bool check_for_bad_items_;
+  bool check_for_unused_overrides_;
 
  private:
   CommonSetup& operator=(const CommonSetup& other);  // Disallow.
 };
 
 // Helper class to setup the build settings and environment for the various
 // commands to run.
 class Setup : public CommonSetup {
  public:
   Setup();
@@ skipping 75 matching lines @@
   void RunPreMessageLoop();
   bool RunPostMessageLoop();
 
   virtual Scheduler* GetScheduler() OVERRIDE;
 
  private:
   Scheduler* scheduler_;
 };
 
 #endif  // TOOLS_GN_SETUP_H_