partial switch over to sp usage of shaders

gm/giantbitmap.cpp

Index: gm/giantbitmap.cpp
diff --git a/gm/giantbitmap.cpp b/gm/giantbitmap.cpp
index 4005359acae3d09f0b4f83b4b86c90a7d5212453..e1ba737d2f6814fdca0f1e0f112046ac91947c0e 100644
--- a/gm/giantbitmap.cpp
+++ b/gm/giantbitmap.cpp
@@ -104,9 +104,7 @@ protected:
             SkScalar scale = 11*SK_Scalar1/12;
             m.setScale(scale, scale);
         }
-        SkShader* s = SkShader::CreateBitmapShader(getBitmap(), fMode, fMode, &m);
-
-        paint.setShader(s)->unref();
+        paint.setShader(SkShader::MakeBitmapShader(getBitmap(), fMode, fMode, &m));
         paint.setFilterQuality(fDoFilter ? kLow_SkFilterQuality : kNone_SkFilterQuality);
 
         canvas->translate(SkIntToScalar(50), SkIntToScalar(50));