Replacing the OVERRIDE with override in tools folder

tools/gn/ninja_target_writer_unittest.cc

 // Copyright 2014 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.
 
 #include <sstream>
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "tools/gn/ninja_target_writer.h"
 #include "tools/gn/target.h"
 #include "tools/gn/test_with_scope.h"
 
 namespace {
 
 class TestingNinjaTargetWriter : public NinjaTargetWriter {
  public:
   TestingNinjaTargetWriter(const Target* target,
                            const Toolchain* toolchain,
                            std::ostream& out)
       : NinjaTargetWriter(target, out) {
   }
 
-  virtual void Run() OVERRIDE {}
+  virtual void Run() override {}
 
   // Make this public so the test can call it.
   OutputFile WriteInputDepsStampAndGetDep(
       const std::vector<const Target*>& extra_hard_deps) {
     return NinjaTargetWriter::WriteInputDepsStampAndGetDep(extra_hard_deps);
   }
 };
 
 }  // namespace
 
@@ skipping 98 matching lines @@
   std::ostringstream stream;
   TestingNinjaTargetWriter writer(&target, setup.toolchain(), stream);
   OutputFile dep =
       writer.WriteInputDepsStampAndGetDep(std::vector<const Target*>());
 
   EXPECT_EQ("obj/foo/target.inputdeps.stamp", dep.value());
   EXPECT_EQ("build obj/foo/target.inputdeps.stamp: stamp "
                 "obj/foo/setup.stamp\n",
             stream.str());
 }