Add public deps to GN

tools/gn/action_target_generator.h

Index: tools/gn/action_target_generator.h
diff --git a/tools/gn/action_target_generator.h b/tools/gn/action_target_generator.h
index aa81c3d22112a009b99a410b8ba6f5d9f05f284b..9f3e22448ca17b3da06f86cf869694e79079d302 100644
--- a/tools/gn/action_target_generator.h
+++ b/tools/gn/action_target_generator.h
@@ -22,12 +22,12 @@ class ActionTargetGenerator : public TargetGenerator {
   virtual void DoRun() OVERRIDE;
 
  private:
-  void FillScript();
-  void FillScriptArgs();
-  void FillDepfile();
+  bool FillScript();
+  bool FillScriptArgs();
+  bool FillDepfile();
 
   // Checks for errors in the outputs variable.
-  void CheckOutputs();
+  bool CheckOutputs();
 
   Target::OutputType output_type_;