Create output directory in skdiff

tools/skdiff_main.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "skdiff.h"
 #include "skdiff_html.h"
 #include "skdiff_utils.h"
 #include "SkBitmap.h"
@@ skipping 387 matching lines @@
 
     if (!baseFiles.isEmpty()) {
         qsort(baseFiles.begin(), baseFiles.count(), sizeof(SkString*),
               SkCastForQSort(compare_file_name_metrics));
     }
     if (!comparisonFiles.isEmpty()) {
         qsort(comparisonFiles.begin(), comparisonFiles.count(),
               sizeof(SkString*), SkCastForQSort(compare_file_name_metrics));
     }
 
+    if (!outputDir.isEmpty()) {
+        sk_mkdir(outputDir.c_str());
+    }
+
     int i = 0;
     int j = 0;
 
     while (i < baseFiles.count() &&
            j < comparisonFiles.count()) {
 
         SkString basePath(baseDir);
         SkString comparisonPath(comparisonDir);
 
         DiffRecord *drp = new DiffRecord;
@@ skipping 431 matching lines @@
     // range [0...255] are wrapped (mod 256).  Do the conversion ourselves, to
     // make sure that we only return 0 when there were no failures.
     return (num_failing_results > 255) ? 255 : num_failing_results;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char * const argv[]) {
     return tool_main(argc, (char**) argv);
 }
 #endif