Change enclosingTextControl to take const Node ptr

third_party/WebKit/Source/core/html/TextControlElement.cpp

Index: third_party/WebKit/Source/core/html/TextControlElement.cpp
diff --git a/third_party/WebKit/Source/core/html/TextControlElement.cpp b/third_party/WebKit/Source/core/html/TextControlElement.cpp
index 91f0510e7cdb1d1dfefa819542462e22bd69961a..1b1bf9d33515b2c7cfc75b66b5dfb1207ae8cf5c 100644
--- a/third_party/WebKit/Source/core/html/TextControlElement.cpp
+++ b/third_party/WebKit/Source/core/html/TextControlElement.cpp
@@ -865,7 +865,7 @@ TextControlElement* enclosingTextControl(const Position& position) {
   return enclosingTextControl(position.computeContainerNode());
 }
 
-TextControlElement* enclosingTextControl(Node* container) {
+TextControlElement* enclosingTextControl(const Node* container) {
   if (!container)
     return nullptr;
   Element* ancestor = container->ownerShadowHost();