[debugger] Add visualization of center rect for drawBitmapNine calls

Review URL: https://codereview.chromium.org/1462643002
diff --git a/src/utils/debugger/SkDrawCommand.cpp b/src/utils/debugger/SkDrawCommand.cpp
index 8be6de9..66f0c14 100644
--- a/src/utils/debugger/SkDrawCommand.cpp
+++ b/src/utils/debugger/SkDrawCommand.cpp
@@ -336,7 +336,8 @@
 }
 
 bool SkDrawBitmapNineCommand::render(SkCanvas* canvas) const {
-    render_bitmap(canvas, fBitmap);
+    SkRect tmp = SkRect::Make(fCenter);
+    render_bitmap(canvas, fBitmap, &tmp);
     return true;
 }