Refactor GN source expansions.

tools/gn/action_values.h

Index: tools/gn/action_values.h
diff --git a/tools/gn/action_values.h b/tools/gn/action_values.h
index 7a70d3311a8339fd34225129461d517ed1fd7298..fcb6acab24da0380dcd55888613f08feb623675c 100644
--- a/tools/gn/action_values.h
+++ b/tools/gn/action_values.h
@@ -10,6 +10,7 @@
 
 #include "base/basictypes.h"
 #include "tools/gn/source_file.h"
+#include "tools/gn/substitution_list.h"
 
 // Holds the values (outputs, args, script name, etc.) for either an action or
 // an action_foreach target.
@@ -23,24 +24,24 @@ class ActionValues {
   void set_script(const SourceFile& s) { script_ = s; }
 
   // Arguments to the script.
-  std::vector<std::string>& args() { return args_; }
-  const std::vector<std::string>& args() const { return args_; }
+  SubstitutionList& args() { return args_; }
+  const SubstitutionList& args() const { return args_; }
 
   // Files created by the script. These are strings rather than SourceFiles
   // since they will often contain {{source expansions}}.
-  std::vector<std::string>& outputs() { return outputs_; }
-  const std::vector<std::string>& outputs() const { return outputs_; }
+  SubstitutionList& outputs() { return outputs_; }
+  const SubstitutionList& outputs() const { return outputs_; }
 
   // Depfile generated by the script.
-  const SourceFile& depfile() const { return depfile_; }
-  bool has_depfile() const { return !depfile_.is_null(); }
-  void set_depfile(const SourceFile& depfile) { depfile_ = depfile; }
+  const SubstitutionPattern& depfile() const { return depfile_; }
+  bool has_depfile() const { return !depfile_.ranges().empty(); }
+  void set_depfile(const SubstitutionPattern& depfile) { depfile_ = depfile; }
 
  private:
   SourceFile script_;
-  std::vector<std::string> args_;
-  std::vector<std::string> outputs_;
-  SourceFile depfile_;
+  SubstitutionList args_;
+  SubstitutionList outputs_;
+  SubstitutionPattern depfile_;
 
   DISALLOW_COPY_AND_ASSIGN(ActionValues);
 };