Windows precompiled header support in GN

tools/gn/test_with_scope.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_TEST_WITH_SCOPE_H_
 #define TOOLS_GN_TEST_WITH_SCOPE_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 25 matching lines @@
   // threadsafe so don't write tests that call print from multiple threads.
   std::string& print_output() { return print_output_; }
 
   // Parse the given string into a label in the default toolchain. This will
   // assert if the label isn't valid (this is intended for hardcoded labels).
   Label ParseLabel(const std::string& str) const;
 
   // Fills in the tools for the given toolchain with reasonable default values.
   // The toolchain in this object will be automatically set up with this
   // function, it is exposed to allow tests to get the same functionality for
-  // other toolchains they make
+  // other toolchains they make.
   static void SetupToolchain(Toolchain* toolchain);
 
+  // Sets the given text command on the given tool, parsing it as a
+  // substitution pattern. This will assert if the input is malformed. This is
+  // designed to help setting up Tools for tests.
+  static void SetCommandForTool(const std::string& cmd, Tool* tool);
+
  private:
   void AppendPrintOutput(const std::string& str);
 
   BuildSettings build_settings_;
   Settings settings_;
   Toolchain toolchain_;
   Scope scope_;
 
   std::string print_output_;
 
@@ skipping 33 matching lines @@
 // default to public visibility.
 class TestTarget : public Target {
  public:
   TestTarget(TestWithScope& setup,
              const std::string& label_string,
              Target::OutputType type);
   ~TestTarget() override;
 };
 
 #endif  // TOOLS_GN_TEST_WITH_SCOPE_H_