add DeferredCanvas mode to SampleApp

samplecode/SampleApp.h

Index: samplecode/SampleApp.h
diff --git a/samplecode/SampleApp.h b/samplecode/SampleApp.h
index 55e3f555a30c15c8f26bb3f7315457ae3b7ea0b8..8fc1a905b1b7cba185fb8ed6148811af97aa4abd 100644
--- a/samplecode/SampleApp.h
+++ b/samplecode/SampleApp.h
@@ -22,6 +22,7 @@ class GrRenderTarget;
 
 class SkCanvas;
 class SkData;
+class SkDeferredCanvas;
 class SkDocument;
 class SkEvent;
 class SkTypeface;
@@ -39,7 +40,7 @@ public:
         kANGLE_DeviceType,
 #endif // SK_ANGLE
 #endif // SK_SUPPORT_GPU
-
+        kDeferred_DeviceType,
         kDeviceTypeCnt
     };
 
@@ -161,6 +162,8 @@ private:
     int fCurrIndex;
 
     SkPictureRecorder fRecorder;
+    SkAutoTDelete<SkSurface> fDeferredSurface;
+    SkAutoTDelete<SkDeferredCanvas> fDeferredCanvas;
     SkPath fClipPath;
 
     SkTouchGesture fGesture;