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/RefCntBench.cpp b/bench/RefCntBench.cpp
index cdc81eb..c8a98e4 100644
--- a/bench/RefCntBench.cpp
+++ b/bench/RefCntBench.cpp
@@ -18,6 +18,7 @@
 class RefCntBench_Stack : public SkBenchmark {
 public:
     RefCntBench_Stack(void* param) : INHERITED(param) {
+        fIsRendering = false;
     }
 protected:
     virtual const char* onGetName() {
@@ -54,6 +55,7 @@
 class RefCntBench_Heap : public SkBenchmark {
 public:
     RefCntBench_Heap(void* param) : INHERITED(param) {
+        fIsRendering = false;
     }
 protected:
     virtual const char* onGetName() {
@@ -79,6 +81,7 @@
 class RefCntBench_New : public SkBenchmark {
 public:
     RefCntBench_New(void* param) : INHERITED(param) {
+        fIsRendering = false;
     }
 protected:
     virtual const char* onGetName() {
@@ -105,6 +108,7 @@
 class WeakRefCntBench_Stack : public SkBenchmark {
 public:
     WeakRefCntBench_Stack(void* param) : INHERITED(param) {
+        fIsRendering = false;
     }
 protected:
     virtual const char* onGetName() {
@@ -134,6 +138,7 @@
 class WeakRefCntBench_Heap : public SkBenchmark {
 public:
     WeakRefCntBench_Heap(void* param) : INHERITED(param) {
+        fIsRendering = false;
     }
 protected:
     virtual const char* onGetName() {
@@ -159,6 +164,7 @@
 class WeakRefCntBench_New : public SkBenchmark {
 public:
     WeakRefCntBench_New(void* param) : INHERITED(param) {
+        fIsRendering = false;
     }
 protected:
     virtual const char* onGetName() {