Add outputs to GN's header checker.

tools/gn/header_checker.h

 // 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.
 
 #ifndef TOOLS_GN_HEADER_CHECKER_H_
 #define TOOLS_GN_HEADER_CHECKER_H_
 
 #include <map>
 #include <set>
 #include <vector>
@@ skipping 40 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(HeaderCheckerTest, IsDependencyOf);
   FRIEND_TEST_ALL_PREFIXES(HeaderCheckerTest,
                            IsDependencyOf_ForwardsDirectDependentConfigs);
   FRIEND_TEST_ALL_PREFIXES(HeaderCheckerTest, CheckInclude);
   FRIEND_TEST_ALL_PREFIXES(HeaderCheckerTest, CheckIncludeAllowCircular);
   FRIEND_TEST_ALL_PREFIXES(HeaderCheckerTest,
                            GetDependentConfigChainProblemIndex);
   ~HeaderChecker();
 
   struct TargetInfo {
-    TargetInfo() : target(NULL), is_public(false) {}
-    TargetInfo(const Target* t, bool p) : target(t), is_public(p) {}
+    TargetInfo() : target(NULL), is_public(false), is_generated(false) {}
+    TargetInfo(const Target* t, bool is_pub, bool is_gen)
+        : target(t),
+          is_public(is_pub),
+          is_generated(is_gen) {
+    }
 
     const Target* target;
+
+    // True if the file is public in the given target.
     bool is_public;
+
+    // True if this file is generated and won't actually exist on disk.
+    bool is_generated;
   };
 
   typedef std::vector<TargetInfo> TargetVector;
   typedef std::map<SourceFile, TargetVector> FileMap;
 
   // Backend for Run() that takes the list of files to check. The errors_ list
   // will be populate on failure.
   void RunCheckOverFiles(const FileMap& flies, bool force_check);
 
   void DoWork(const Target* target, const SourceFile& file);
@@ skipping 77 matching lines @@
   // These are mutable during runtime and require locking.
 
   base::Lock lock_;
 
   std::vector<Err> errors_;
 
   DISALLOW_COPY_AND_ASSIGN(HeaderChecker);
 };
 
 #endif  // TOOLS_GN_HEADER_CHECKER_H_