flag to use const& instead of const* for src-rect

BUG=skia:

Review URL: https://codereview.chromium.org/1272713005
diff --git a/src/utils/debugger/SkDrawCommand.cpp b/src/utils/debugger/SkDrawCommand.cpp
index 15fc9ca..8e1612f 100644
--- a/src/utils/debugger/SkDrawCommand.cpp
+++ b/src/utils/debugger/SkDrawCommand.cpp
@@ -131,7 +131,7 @@
                                   yScale * input.height());
 
     canvas->clear(0xFFFFFFFF);
-    canvas->drawBitmapRect(input, dst);
+    canvas->drawBitmapRect(input, dst, nullptr);
 
     if (srcRect) {
         SkRect r = SkRect::MakeLTRB(srcRect->fLeft * xScale + SK_Scalar1,
@@ -352,7 +352,7 @@
 }
 
 void SkDrawBitmapRectCommand::execute(SkCanvas* canvas) const {
-    canvas->drawBitmapRect(fBitmap, this->srcRect(), fDst, fPaintPtr, fConstraint);
+    canvas->legacy_drawBitmapRect(fBitmap, this->srcRect(), fDst, fPaintPtr, fConstraint);
 }
 
 bool SkDrawBitmapRectCommand::render(SkCanvas* canvas) const {
@@ -405,7 +405,7 @@
 }
 
 void SkDrawImageRectCommand::execute(SkCanvas* canvas) const {
-    canvas->drawImageRect(fImage, fSrc.getMaybeNull(), fDst, fPaint.getMaybeNull(), fConstraint);
+    canvas->legacy_drawImageRect(fImage, fSrc.getMaybeNull(), fDst, fPaint.getMaybeNull(), fConstraint);
 }
 
 bool SkDrawImageRectCommand::render(SkCanvas* canvas) const {