Add testonly flag to GN

tools/gn/target.h

Index: tools/gn/target.h
diff --git a/tools/gn/target.h b/tools/gn/target.h
index 9b7ff6d10201778c13e88dbe0b4c14bd1f0d4775..19cb49284778af1c60f0a36847549068c7e9fe45 100644
--- a/tools/gn/target.h
+++ b/tools/gn/target.h
@@ -53,7 +53,7 @@ class Target : public Item {
   // Item overrides.
   virtual Target* AsTarget() OVERRIDE;
   virtual const Target* AsTarget() const OVERRIDE;
-  virtual void OnResolved() OVERRIDE;
+  virtual bool OnResolved(Err* err) OVERRIDE;
 
   OutputType output_type() const { return output_type_; }
   void set_output_type(OutputType t) { output_type_ = t; }
@@ -91,6 +91,9 @@ class Target : public Item {
   const FileList& public_headers() const { return public_headers_; }
   FileList& public_headers() { return public_headers_; }
 
+  bool testonly() const { return testonly_; }
+  void set_testonly(bool value) { testonly_ = value; }
+
   // Compile-time extra dependencies.
   const FileList& inputs() const { return inputs_; }
   FileList& inputs() { return inputs_; }
@@ -198,6 +201,8 @@ class Target : public Item {
   }
 
  private:
+  void ExpandGroups();
+
   // Pulls necessary information from dependencies to this one when all
   // dependencies have been resolved.
   void PullDependentTargetInfo();
@@ -210,6 +215,10 @@ class Target : public Item {
   // Fills the link and dependency output files when a target is resolved.
   void FillOutputFiles();
 
+  // Validates the given thing when a target is resolved.
+  bool CheckVisibility(Err* err) const;
+  bool CheckTestonly(Err* err) const;
+
   OutputType output_type_;
   std::string output_name_;
   std::string output_extension_;
@@ -217,6 +226,7 @@ class Target : public Item {
   FileList sources_;
   bool all_headers_public_;
   FileList public_headers_;
+  bool testonly_;
   FileList inputs_;
   FileList data_;