Adding new benchmark to test image decoding performance.

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"
 
 DEFINE_string(config, "565 8888 gpu nonrendering angle nvprmsaa4 ",
               "Options: 565 8888 pdf gpu nonrendering msaa4 msaa16 nvprmsaa4 nvprmsaa16 "
               "gpudft gpunull gpudebug angle mesa (and many more)");
 
 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(gpuAPI, "", "Force use of specific gpu API.  Using \"gl\" "
               "forces OpenGL API. Using \"gles\" forces OpenGL ES API. "
               "Defaults to empty string, which selects the API native to the "
               "system.");
 
+DEFINE_string(images, "resources", "Directory of images to decode.");
+
 DEFINE_bool2(leaks, l, false, "show leaked ref cnt'd objects.");
 
 DEFINE_string2(match, m, NULL,
                "[~][^]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"
@@ skipping 12 matching lines @@
 
 DEFINE_bool2(veryVerbose, V, false, "tell individual tests to be verbose.");
 
 DEFINE_string2(writePath, w, "", "If set, write bitmaps here as .pngs.");
 
 DEFINE_string(key, "",
               "Space-separated key/value pairs to add to JSON identifying this builder.");
 DEFINE_string(properties, "",
               "Space-separated key/value pairs to add to JSON identifying this run.");