Bug 1275831 - part5: fix NOISY_REFLOW_REASON block layout debug flag. r=dholbert

Add back a helper function for listing framelist tags. This function has been
called under other flags as well.

MozReview-Commit-ID: 5smFQ70tVRO

--HG--
extra : rebase_source : 95ba1c2cfaee330368bb8557605a58b360efc4d8

layout/generic/nsIFrame.h

@@ -3468,6 +3468,11 @@ public:
     ListTag(t, aFrame);
     fputs(t.get(), out);
   }
+  static void ListTag(FILE* out, const nsFrameList& aFrameList) {
+    for (nsIFrame* frame : aFrameList) {
+      ListTag(out, frame);
+    }
+  }
   void ListTag(nsACString& aTo) const;
   nsAutoCString ListTag() const {
     nsAutoCString tag;