Add optional debugging output of what paint chunks go into what layers.

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

Index: third_party/WebKit/Source/platform/graphics/paint/DisplayItemList.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/paint/DisplayItemList.cpp b/third_party/WebKit/Source/platform/graphics/paint/DisplayItemList.cpp
index 327cb993e215d3b5c786ea93f1a4facd58145721..1b2c9b31d142a2da86aa9038e3d81ef17d032f19 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/DisplayItemList.cpp
+++ b/third_party/WebKit/Source/platform/graphics/paint/DisplayItemList.cpp
@@ -66,7 +66,14 @@ std::unique_ptr<JSONArray> DisplayItemList::subsequenceAsJSON(
 #ifndef NDEBUG
     StringBuilder stringBuilder;
     displayItem.dumpPropertiesAsDebugString(stringBuilder);
-    json->setString("properties", stringBuilder.toString());
+
+    if (options & ShownOnlyDisplayItemTypes) {
+      json->setString("type",
+                      DisplayItem::typeAsDebugString(displayItem.getType()));
+    } else {
+      json->setString("properties", stringBuilder.toString());
+    }
+
 #endif
     if (displayItem.hasValidClient()) {
 #if CHECK_DISPLAY_ITEM_CLIENT_ALIVENESS
@@ -77,12 +84,10 @@ std::unique_ptr<JSONArray> DisplayItemList::subsequenceAsJSON(
 
       if (options & ShowClientDebugName) {
 #endif
-#ifdef NDEBUG
         json->setString(
             "clientDebugName",
             String::format("clientDebugName: \"%s\"",
                            displayItem.client().debugName().ascii().data()));
-#endif
       }
 #ifndef NDEBUG
       if ((options & ShowPictures) && displayItem.isDrawing()) {