Remove redundant debug output from DrawingDisplayItem

visualRect is already recorded in DisplayItem::PropertiesAsJSON.

Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: I9acc521e96f6bb077a7200ca1bbfbb3f8691e4f6
Reviewed-on: https://chromium-review.googlesource.com/843477
Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526093}

third_party/WebKit/Source/platform/graphics/paint/DrawingDisplayItem.cpp

@@ -36,7 +36,6 @@ bool DrawingDisplayItem::DrawsContent() const {
 #if DCHECK_IS_ON()
 void DrawingDisplayItem::PropertiesAsJSON(JSONObject& json) const {
   DisplayItem::PropertiesAsJSON(json);
-  json.SetString("rect", VisualRect().ToString());
   json.SetBoolean("opaque", known_to_be_opaque_);
 }
 #endif