Implement tracking of BUILD.gn files used to define target, toolchain or

tools/gn/target.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_TARGET_H_
 #define TOOLS_GN_TARGET_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 37 matching lines @@
   };
 
   enum DepsIterationType {
     DEPS_ALL,  // Iterates through all public, private, and data deps.
     DEPS_LINKED,  // Iterates through all non-data dependencies.
   };
 
   typedef std::vector<SourceFile> FileList;
   typedef std::vector<std::string> StringVector;
 
-  Target(const Settings* settings, const Label& label);
+  Target(const Settings* settings,
+         const Label& label,
+         const InputFileSet& input_files);
   ~Target() override;
 
   // Returns a string naming the output type.
   static const char* GetStringForOutputType(OutputType type);
 
   // Item overrides.
   Target* AsTarget() override;
   const Target* AsTarget() const override;
   bool OnResolved(Err* err) override;
 
@@ skipping 324 matching lines @@
   OutputFile link_output_file_;
   OutputFile dependency_output_file_;
   std::vector<OutputFile> runtime_outputs_;
 
   DISALLOW_COPY_AND_ASSIGN(Target);
 };
 
 extern const char kExecution_Help[];
 
 #endif  // TOOLS_GN_TARGET_H_