Fix VisualBench to hold onto a surface

tools/VisualBench/VisualBench.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
  */
 
 #include "VisualBench.h"
 
@@ skipping 56 matching lines @@
 VisualBench::~VisualBench() {
     INHERITED::detach();
 }
 
 void VisualBench::setTitle() {
     SkString title("VisualBench");
     INHERITED::setTitle(title.c_str());
 }
 
 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() {
     this->setColorType(kRGBA_8888_SkColorType);
     this->setVisibleP(true);
     this->setClipToBounds(false);
 
     if (FLAGS_fullscreen) {
         if (!this->makeFullscreen()) {
             SkDebugf("Could not go fullscreen!");
@@ skipping 179 matching lines @@
 
 void application_term() {
     SkEvent::Term();
     SkGraphics::Term();
 }
 
 SkOSWindow* create_sk_window(void* hwnd, int argc, char** argv) {
     return new VisualBench(hwnd, argc, argv);
 }