use surface in SkView/SampleApp

samplecode/SampleApp.h

Index: samplecode/SampleApp.h
diff --git a/samplecode/SampleApp.h b/samplecode/SampleApp.h
index e08ff8a8f4ff325fc8567fe027b0c0e57f88a6db..abb1f2400211481554c4ded7cf50c191298a2534 100644
--- a/samplecode/SampleApp.h
+++ b/samplecode/SampleApp.h
@@ -76,7 +76,7 @@ public:
 
         // called before drawing. should install correct device
         // type on the canvas. Will skip drawing if returns false.
-        virtual SkCanvas* createCanvas(DeviceType dType, SampleWindow* win) = 0;
+        virtual SkSurface* createSurface(DeviceType dType, SampleWindow* win) = 0;
 
         // called after drawing, should get the results onto the
         // screen.
@@ -100,18 +100,18 @@ public:
     SampleWindow(void* hwnd, int argc, char** argv, DeviceManager*);
     virtual ~SampleWindow();
 
-    virtual SkCanvas* createCanvas() SK_OVERRIDE {
-        SkCanvas* canvas = NULL;
+    virtual SkSurface* createSurface() SK_OVERRIDE {
+        SkSurface* surface = NULL;
         if (fDevManager) {
-            canvas = fDevManager->createCanvas(fDeviceType, this);
+            surface = fDevManager->createSurface(fDeviceType, this);
         }
-        if (NULL == canvas) {
-            canvas = this->INHERITED::createCanvas();
+        if (NULL == surface) {
+            surface = this->INHERITED::createSurface();
         }
-        return canvas;
+        return surface;
     }
 
-    virtual void draw(SkCanvas* canvas);
+    virtual void draw(SkCanvas*) SK_OVERRIDE;
 
     void setDeviceType(DeviceType type);
     void toggleRendering();