Make DocumentOrderedMap take a const reference for scope

third_party/WebKit/Source/core/dom/TreeScope.cpp

Index: third_party/WebKit/Source/core/dom/TreeScope.cpp
diff --git a/third_party/WebKit/Source/core/dom/TreeScope.cpp b/third_party/WebKit/Source/core/dom/TreeScope.cpp
index f1aeb2839c84de87fb26f1e7857026b44f2f1f61..4df48fd20c3bb623e90a8d9e70842e78e84a0401 100644
--- a/third_party/WebKit/Source/core/dom/TreeScope.cpp
+++ b/third_party/WebKit/Source/core/dom/TreeScope.cpp
@@ -123,7 +123,7 @@ Element* TreeScope::getElementById(const AtomicString& element_id) const {
     return nullptr;
   if (!elements_by_id_)
     return nullptr;
-  return elements_by_id_->GetElementById(element_id, this);
+  return elements_by_id_->GetElementById(element_id, *this);
 }
 
 const HeapVector<Member<Element>>& TreeScope::GetAllElementsById(
@@ -134,7 +134,7 @@ const HeapVector<Member<Element>>& TreeScope::GetAllElementsById(
     return empty_vector;
   if (!elements_by_id_)
     return empty_vector;
-  return elements_by_id_->GetAllElementsById(element_id, this);
+  return elements_by_id_->GetAllElementsById(element_id, *this);
 }
 
 void TreeScope::AddElementById(const AtomicString& element_id,
@@ -192,7 +192,7 @@ HTMLMapElement* TreeScope::GetImageMap(const String& url) const {
   size_t hash_pos = url.find('#');
   String name = hash_pos == kNotFound ? url : url.Substring(hash_pos + 1);
   return toHTMLMapElement(
-      image_maps_by_name_->GetElementByMapName(AtomicString(name), this));
+      image_maps_by_name_->GetElementByMapName(AtomicString(name), *this));
 }
 
 static bool PointWithScrollAndZoomIfPossible(const Document& document,
@@ -453,11 +453,10 @@ unsigned short TreeScope::ComparePosition(const TreeScope& other_scope) const {
 
   // There was no difference between the two parent chains, i.e., one was a
   // subset of the other. The shorter chain is the ancestor.
-  return index1 < index2
-             ? Node::kDocumentPositionFollowing |
-                   Node::kDocumentPositionContainedBy
-             : Node::kDocumentPositionPreceding |
-                   Node::kDocumentPositionContains;
+  return index1 < index2 ? Node::kDocumentPositionFollowing |
+                               Node::kDocumentPositionContainedBy
+                         : Node::kDocumentPositionPreceding |
+                               Node::kDocumentPositionContains;
 }
 
 const TreeScope* TreeScope::CommonAncestorTreeScope(