Hide canonicalPosition in VisiblePosition from header file

Source/core/editing/VisiblePosition.cpp

Index: Source/core/editing/VisiblePosition.cpp
diff --git a/Source/core/editing/VisiblePosition.cpp b/Source/core/editing/VisiblePosition.cpp
index 046f5b6883f9c9c47e687b62db901d27e73890bd..6d5b4ab4690f062039d4262474898af445454412 100644
--- a/Source/core/editing/VisiblePosition.cpp
+++ b/Source/core/editing/VisiblePosition.cpp
@@ -58,6 +58,8 @@ VisiblePosition::VisiblePosition(const PositionWithAffinity& positionWithAffinit
     init(positionWithAffinity.position(), positionWithAffinity.affinity());
 }
 
+static Position canonicalPosition(const Position& passedPosition);

[tkent, 2015/06/19 03:53:58]

Usually we don't add forward declaration for a static function.  But the
function is too large to move here.
so, lgtm.

+
 void VisiblePosition::init(const Position& position, EAffinity affinity)
 {
     m_affinity = affinity;
@@ -553,7 +555,7 @@ static Position canonicalizeCandidate(const Position& candidate)
     return candidate;
 }
 
-Position VisiblePosition::canonicalPosition(const Position& passedPosition)
+static Position canonicalPosition(const Position& passedPosition)
 {
     // Sometimes updating selection positions can be extremely expensive and occur
     // frequently.  Often calling preventDefault on mousedown events can avoid