Fix Mac clang linker

tools/flags/SkCommonFlags.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCommonFlags.h"
 #include "SkOSFile.h"
 
 DEFINE_bool(cpu, true, "master switch for running CPU-bound work.");
 
 DEFINE_bool(dryRun, false,
             "just print the tests that would be run, without actually running them.");
 
 DEFINE_bool(gpu, true, "master switch for running GPU-bound work.");
 
 DEFINE_string(images, "", "List of images and/or directories to decode. A directory with no images"
                           " is treated as a fatal error.");
 
 DEFINE_string(colorImages, "", "List of images and/or directories to decode with color correction. "
                                "A directory with no images is treated as a fatal error.");
 
+DEFINE_bool(simpleCodec, false, "Runs of a subset of the codec tests.  "
+                                "For DM, this means no scaling or subsetting, always using the "
+                                "canvas color type.  "
+                                "For nanobench, this means always N32, Premul or Opaque.");
+
 DEFINE_string2(match, m, nullptr,
                "[~][^]substring[$] [...] of GM name to run.\n"
                "Multiple matches may be separated by spaces.\n"
                "~ causes a matching GM to always be skipped\n"
                "^ requires the start of the GM to match\n"
                "$ requires the end of the GM to match\n"
                "^ and $ requires an exact match\n"
                "If a GM does not match any list entry,\n"
                "it is skipped unless some list entry starts with ~");
 
@@ skipping 58 matching lines @@
                 SkDebugf("No supported images found in %s!\n", flag);
                 return false;
             }
         } else {
             // Also add the value if it is a single image
             output->push_back() = flag;
         }
     }
     return true;
 }