Add testonly flag to GN

tools/gn/target_generator.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_GENERATOR_H_
 #define TOOLS_GN_TARGET_GENERATOR_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 52 matching lines @@
 
   Target* target_;
   Scope* scope_;
   const FunctionCallNode* function_call_;
   Err* err_;
 
  private:
   void FillDependentConfigs();  // Includes all types of dependent configs.
   void FillData();
   void FillDependencies();  // Includes data dependencies.
+  void FillTestonly();
 
   // Reads configs/deps from the given var name, and uses the given setting on
   // the target to save them.
   void FillGenericConfigs(const char* var_name,
                           UniqueVector<LabelConfigPair>* dest);
   void FillGenericDeps(const char* var_name, LabelTargetVector* dest);
 
   void FillForwardDependentConfigs();
 
   DISALLOW_COPY_AND_ASSIGN(TargetGenerator);
 };
 
 #endif  // TOOLS_GN_TARGET_GENERATOR_H_