Major bench refactoring.
   - Use FLAGS_.
   - Remove outer repeat loop.
   - Tune inner loop automatically.

BUG=skia:1590
R=epoger@google.com, scroggo@google.com

Review URL: https://codereview.chromium.org/23478013

git-svn-id: http://skia.googlecode.com/svn/trunk@11187 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/MergeBench.cpp b/bench/MergeBench.cpp
index 992507d..98a918a 100644
--- a/bench/MergeBench.cpp
+++ b/bench/MergeBench.cpp
@@ -38,7 +38,9 @@
                               SkRect::MakeWH(FILTER_WIDTH_LARGE, FILTER_HEIGHT_LARGE);
         SkPaint paint;
         paint.setImageFilter(mergeBitmaps())->unref();
-        canvas->drawRect(r, paint);
+        for (int i = 0; i < this->getLoops(); i++) {
+            canvas->drawRect(r, paint);
+        }
     }
 
 private: