Add GN variables for controlling header checking.

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 21 matching lines @@
  public:
   HeaderChecker(const BuildSettings* build_settings,
                 const std::vector<const Target*>& targets);
 
   // Runs the check. The targets in to_check will be checked. If this list is
   // empty, all targets will be checked.
   //
   // This assumes that the current thread already has a message loop. On
   // error, fills the given vector with the errors and returns false. Returns
   // true on success.
+  //
+  // force_check, if true, will override targets opting out of header checking
+  // with "check_includes = false" and will check them anyway.
   bool Run(const std::vector<const Target*>& to_check,
+           bool force_check,
            std::vector<Err>* errors);
 
  private:
   friend class base::RefCountedThreadSafe<HeaderChecker>;
   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) {}
 
     const Target* target;
     bool is_public;
   };
 
   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);
+  void RunCheckOverFiles(const FileMap& flies, bool force_check);
 
   void DoWork(const Target* target, const SourceFile& file);
 
   // Adds the sources and public files from the given target to the given map.
   static void AddTargetToFileMap(const Target* target, FileMap* dest);
 
   // Returns true if the given file is in the output directory.
   bool IsFileInOuputDir(const SourceFile& file) const;
 
   // Resolves the contents of an include to a SourceFile.
@@ skipping 69 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_