Let SkBenchmark classes specify that they do no rendering.
Doing this gives us a 15-20% speedup in bench cycle time.
Here again I'm just picking the easy targets.

http://codereview.appspot.com/6500115/



git-svn-id: http://skia.googlecode.com/svn/trunk@5525 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/RegionBench.cpp b/bench/RegionBench.cpp
index 7b9e2d4..7a306e9 100644
--- a/bench/RegionBench.cpp
+++ b/bench/RegionBench.cpp
@@ -100,6 +100,7 @@
             fA.op(randrect(rand), SkRegion::kXOR_Op);
             fB.op(randrect(rand), SkRegion::kXOR_Op);
         }
+        fIsRendering = false;
     }
 
 protected: