Fix VisualBench to hold onto a surface

tools/VisualBench/VisualBench.cpp

Index: tools/VisualBench/VisualBench.cpp
diff --git a/tools/VisualBench/VisualBench.cpp b/tools/VisualBench/VisualBench.cpp
index 6501aa36b2bcaaf6df6a05d06687601f80ee97be..136162aece9f554f3f35571119088f1a6ed1457f 100644
--- a/tools/VisualBench/VisualBench.cpp
+++ b/tools/VisualBench/VisualBench.cpp
@@ -74,8 +74,13 @@ void VisualBench::setTitle() {
 }
 
 SkSurface* VisualBench::createSurface() {
-    SkSurfaceProps props(INHERITED::getSurfaceProps());
-    return SkSurface::NewRenderTargetDirect(fRenderTarget, &props);
+    if (!fSurface) {
+        SkSurfaceProps props(INHERITED::getSurfaceProps());
+        fSurface.reset(SkSurface::NewRenderTargetDirect(fRenderTarget, &props));
+    }
+
+    // The caller will wrap the SkSurface in an SkAutoTUnref
+    return SkRef(fSurface.get());
 }
 
 bool VisualBench::setupBackend() {