guard to remove DrawBitmapRectFlags

BUG=skia:

Review URL: https://codereview.chromium.org/1235393003
diff --git a/src/utils/SkNinePatch.cpp b/src/utils/SkNinePatch.cpp
index ce8d480..4a5308b 100644
--- a/src/utils/SkNinePatch.cpp
+++ b/src/utils/SkNinePatch.cpp
@@ -136,7 +136,7 @@
     const int numYStretch = (numYDivs + 1) >> 1;
 
     if (numXStretch < 1 && numYStretch < 1) {
-        canvas->drawBitmapRect(bitmap, NULL, bounds, paint);
+        canvas->drawBitmapRect(bitmap, bounds, paint);
         return;
     }
 
@@ -293,7 +293,7 @@
             s.fRight = srcX[x+1];
             d.fLeft = dstX[x];
             d.fRight = dstX[x+1];
-            canvas->drawBitmapRect(bitmap, &s, d, paint);
+            canvas->drawBitmapRect(bitmap, s, d, paint);
         }
     }
 }
diff --git a/src/utils/debugger/SkDrawCommand.cpp b/src/utils/debugger/SkDrawCommand.cpp
index 5f0f74f..1d28d2e 100644
--- a/src/utils/debugger/SkDrawCommand.cpp
+++ b/src/utils/debugger/SkDrawCommand.cpp
@@ -129,7 +129,7 @@
                                   yScale * input.height());
 
     canvas->clear(0xFFFFFFFF);
-    canvas->drawBitmapRect(input, NULL, dst);
+    canvas->drawBitmapRect(input, dst);
 
     if (srcRect) {
         SkRect r = SkRect::MakeLTRB(srcRect->fLeft * xScale + SK_Scalar1,