Move parentEditingBoundary() to VisibileUnits.cpp from Position.cpp.

This patch moves |parentEditingBoundary()| to "VisibleUnits.{cpp,h}" from
"Position.{cpp,h}" with |nonShadowBoundaryParentNode()| which is used only by
|parentEditingBoundary()| to cleanup "Position.{cpp,h}" for improving code
health, since |parentEditingBoundary()| is used only in "VisibleUnits.cpp".

BUG=518738
TEST=n/a; no behavior changes

Review URL: https://codereview.chromium.org/1288063008

git-svn-id: svn://svn.chromium.org/blink/trunk@200907 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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

@@ -462,41 +462,6 @@ static bool atEditingBoundary(const PositionAlgorithm<Strategy> positions)
         && prevPosition.isNotNull() && !prevPosition.anchorNode()->hasEditableStyle();
 }
 
-template <typename Strategy>
-static ContainerNode* nonShadowBoundaryParentNode(Node* node)
-{
-    ContainerNode* parent = Strategy::parent(*node);
-    return parent && !parent->isShadowRoot() ? parent : nullptr;
-}
-
-template <typename Strategy>
-static Node* parentEditingBoundaryAlgorithm(const PositionAlgorithm<Strategy>& position)
-{
-    Node* const anchorNode = position.anchorNode();
-    if (!anchorNode)
-        return nullptr;
-
-    Node* documentElement = anchorNode->document().documentElement();
-    if (!documentElement)
-        return nullptr;
-
-    Node* boundary = position.computeContainerNode();
-    while (boundary != documentElement && nonShadowBoundaryParentNode<Strategy>(boundary) && anchorNode->hasEditableStyle() == Strategy::parent(*boundary)->hasEditableStyle())
-        boundary = nonShadowBoundaryParentNode<Strategy>(boundary);
-
-    return boundary;
-}
-
-Node* parentEditingBoundary(const Position& position)
-{
-    return parentEditingBoundaryAlgorithm<EditingStrategy>(position);
-}
-
-Node* parentEditingBoundary(const PositionInComposedTree& position)
-{
-    return parentEditingBoundaryAlgorithm<EditingInComposedTreeStrategy>(position);
-}
-
 template <typename Strategy>
 bool PositionAlgorithm<Strategy>::atStartOfTree() const
 {

third_party/WebKit/Source/core/editing/Position.h

@@ -235,11 +235,6 @@ extern template class CORE_EXTERN_TEMPLATE_EXPORT PositionAlgorithm<EditingInCom
 using Position = PositionAlgorithm<EditingStrategy>;
 using PositionInComposedTree = PositionAlgorithm<EditingInComposedTreeStrategy>;
 
-// TODO(yosin) We should make |parentEditingBoundary()| as static function
-// in "VisibleUnits.cpp", since it is used only there.
-CORE_EXPORT Node* parentEditingBoundary(const Position&);
-CORE_EXPORT Node* parentEditingBoundary(const PositionInComposedTree&);
-
 template <typename Strategy>
 bool operator==(const PositionAlgorithm<Strategy>& a, const PositionAlgorithm<Strategy>& b)
 {

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

@@ -455,6 +455,30 @@ VisiblePosition rightWordPosition(const VisiblePosition& visiblePosition, bool s
     return rightWordBreak;
 }
 
+template <typename Strategy>
+static ContainerNode* nonShadowBoundaryParentNode(Node* node)
+{
+    ContainerNode* parent = Strategy::parent(*node);
+    return parent && !parent->isShadowRoot() ? parent : nullptr;
+}
+
+template <typename Strategy>
+static Node* parentEditingBoundary(const PositionAlgorithm<Strategy>& position)
+{
+    Node* const anchorNode = position.anchorNode();
+    if (!anchorNode)
+        return nullptr;
+
+    Node* documentElement = anchorNode->document().documentElement();
+    if (!documentElement)
+        return nullptr;
+
+    Node* boundary = position.computeContainerNode();
+    while (boundary != documentElement && nonShadowBoundaryParentNode<Strategy>(boundary) && anchorNode->hasEditableStyle() == Strategy::parent(*boundary)->hasEditableStyle())
+        boundary = nonShadowBoundaryParentNode<Strategy>(boundary);
+
+    return boundary;
+}
 
 enum BoundarySearchContextAvailability { DontHaveMoreContext, MayHaveMoreContext };