Provide an option in bench_pictures to count pixel ram.

gm/factory.cpp

Index: gm/factory.cpp
diff --git a/gm/factory.cpp b/gm/factory.cpp
index b55532ee8d0384df6e512c77d169270bdd7541ee..f4e8ae3b883fbbd72108131de24c01b90ed338fa 100644
--- a/gm/factory.cpp
+++ b/gm/factory.cpp
@@ -42,7 +42,7 @@ protected:
             SkBitmapFactory factory(&SkImageDecoder::DecodeMemoryToTarget);
             // Create a cache which will boot the pixels out anytime the
             // bitmap is unlocked.
-            SkAutoTUnref<SkLruImageCache> cache(SkNEW_ARGS(SkLruImageCache, (0)));
+            SkAutoTUnref<SkLruImageCache> cache(SkNEW_ARGS(SkLruImageCache, (1)));
             factory.setImageCache(cache);
             factory.installPixelRef(data, &fBitmap);
         }