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/MatrixBench.cpp b/bench/MatrixBench.cpp
index d8e2137..1a85172 100644
--- a/bench/MatrixBench.cpp
+++ b/bench/MatrixBench.cpp
@@ -16,6 +16,7 @@
 public:
     MatrixBench(void* param, const char name[]) : INHERITED(param) {
         fName.printf("matrix_%s", name);
+        fIsRendering = false;
     }
 
     virtual void performTest() = 0;