Make Position::FirstPositionInNode() to take const Node& instead of Node*

third_party/WebKit/Source/core/editing/SurroundingText.cpp

Index: third_party/WebKit/Source/core/editing/SurroundingText.cpp
diff --git a/third_party/WebKit/Source/core/editing/SurroundingText.cpp b/third_party/WebKit/Source/core/editing/SurroundingText.cpp
index 68e561ed1d9a207ce4c87d1c43b4a7af1f8bd5a8..7e9926dd7e6693f3bf58d8d0f66d208bcc7ee036 100644
--- a/third_party/WebKit/Source/core/editing/SurroundingText.cpp
+++ b/third_party/WebKit/Source/core/editing/SurroundingText.cpp
@@ -92,7 +92,7 @@ void SurroundingText::Initialize(const Position& start_position,
   // starts at the document's or input element's start and ends at the selection
   // start and will be updated.
   BackwardsCharacterIterator backwards_iterator(
-      Position::FirstPositionInNode(root_element).ParentAnchoredEquivalent(),
+      Position::FirstPositionInNode(*root_element).ParentAnchoredEquivalent(),
       start_position,
       TextIteratorBehavior::Builder().SetStopsOnFormControls(true).Build());
   if (!backwards_iterator.AtEnd())