guard to remove DrawBitmapRectFlags

BUG=skia:

Review URL: https://codereview.chromium.org/1235393003
diff --git a/samplecode/SampleBitmapRect.cpp b/samplecode/SampleBitmapRect.cpp
index 123bfb8..b6e629c 100644
--- a/samplecode/SampleBitmapRect.cpp
+++ b/samplecode/SampleBitmapRect.cpp
@@ -131,7 +131,7 @@
 
         for (int i = 0; i < 2; ++i) {
             paint.setFilterQuality(1 == i ? kLow_SkFilterQuality : kNone_SkFilterQuality);
-            canvas->drawBitmapRectToRect(bitmap, &srcR, fDstR[i], &paint);
+            canvas->drawBitmapRect(bitmap, &srcR, fDstR[i], &paint);
             canvas->drawRect(fDstR[i], paint);
         }
     }
@@ -225,7 +225,7 @@
 
         for (int i = 0; i < 2; ++i) {
             paint.setFilterQuality(1 == i ? kLow_SkFilterQuality : kNone_SkFilterQuality);
-            canvas->drawBitmapRectToRect(fBitmap, &fSrcR, fDstR[i], &paint);
+            canvas->drawBitmapRect(fBitmap, &fSrcR, fDstR[i], &paint);
             canvas->drawRect(fDstR[i], paint);
         }
     }