update example

src/views/SkWindow.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkWindow.h"
 #include "SkCanvas.h"
 #include "SkOSMenu.h"
@@ skipping 323 matching lines @@
                 fClicks.remove(index);
                 handled = true;
             }
             break;
         default:
             // Do nothing
             break;
     }
     return handled;
 }
+
+#if SK_SUPPORT_GPU
+
+#include "gl/GrGLInterface.h"
+#include "gl/GrGLUtil.h"
+#include "SkGr.h"
+
+GrRenderTarget* SkWindow::renderTarget(const AttachmentInfo& attachmentInfo,
+        const GrGLInterface* interface, GrContext* grContext) {
+    GrBackendRenderTargetDesc desc;
+    desc.fWidth = SkScalarRoundToInt(this->width());
+    desc.fHeight = SkScalarRoundToInt(this->height());
+    desc.fConfig = kSkia8888_GrPixelConfig;
+    desc.fOrigin = kBottomLeft_GrSurfaceOrigin;
+    desc.fSampleCnt = attachmentInfo.fSampleCount;
+    desc.fStencilBits = attachmentInfo.fStencilBits;
+    GrGLint buffer;
+    GR_GL_GetIntegerv(interface, GR_GL_FRAMEBUFFER_BINDING, &buffer);
+    desc.fRenderTargetHandle = buffer;
+    return grContext->wrapBackendRenderTarget(desc);
+}
+
+#endif