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/InterpBench.cpp b/bench/InterpBench.cpp
index f8f463b..b689c72 100644
--- a/bench/InterpBench.cpp
+++ b/bench/InterpBench.cpp
@@ -20,6 +20,7 @@
         fName.printf("interp_%s", name);
         fFx = 3.3f;
         fDx = 0.1257f;
+        fIsRendering = false;
     }
 
     virtual void performTest(int16_t dst[], float x, float dx, int count) = 0;