Clean up unused constant globals

tools/gn/command_gyp.cc

 // 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.
 
 #include <fstream>
 
 #include "base/atomicops.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ skipping 18 matching lines @@
 // Suppress output on success.
 const char kSwitchQuiet[] = "q";
 
 // Skip actually executing GYP. This is for when you're working on the GN
 // build and don't want to wait for GYP to regenerate. All GN files are
 // regenerated, but the GYP ones are not.
 const char kSwitchNoGyp[] = "no-gyp";
 
 // Where to have GYP write its outputs.
 const char kDirOut[] = "out.gn";
-const char kSourceDirOut[] = "//out.gn/";
 
 // We'll do the GN build to here.
 const char kBuildSourceDir[] = "//out.gn/Debug/";
 
 // File that GYP will write dependency information to.
 const char kGypDepsSourceFileName[] = "//out.gn/gyp_deps.txt";
 
 void TargetResolvedCallback(base::subtle::Atomic32* write_counter,
                             const Target* target) {
   base::subtle::NoBarrier_AtomicIncrement(write_counter, 1);
@@ skipping 315 matching lines @@
         base::IntToString((end_gyp_time - begin_time).InMilliseconds()) +
         "ms)\n";
 
     OutputString(stats);
   }
 
   return 0;
 }
 
 }  // namespace commands