Move DOMSelection.[cpp/h] from core/page to core/editing

Source/core/core.gypi

Index: Source/core/core.gypi
diff --git a/Source/core/core.gypi b/Source/core/core.gypi
index 7ed0e3cb0d83488f2ce374de3822ac34f951cba0..01911d8d5f36ef620119efe281e2eb780cc73768 100644
--- a/Source/core/core.gypi
+++ b/Source/core/core.gypi
@@ -93,6 +93,7 @@
             'dom/URL.idl',
             'dom/XMLDocument.idl',
             'dom/shadow/ShadowRoot.idl',
+            'editing/Selection.idl',
             'events/AnimationPlayerEvent.idl',
             'events/ApplicationCacheErrorEvent.idl',
             'events/AutocompleteErrorEvent.idl',
@@ -284,7 +285,6 @@
             'loader/appcache/ApplicationCache.idl',
             'page/EventSource.idl',
             'page/PagePopupController.idl',
-            'page/Selection.idl',
             'plugins/MimeType.idl',
             'plugins/MimeTypeArray.idl',
             'plugins/Plugin.idl',
@@ -995,6 +995,8 @@
             'editing/DeleteFromTextNodeCommand.cpp',
             'editing/DeleteFromTextNodeCommand.h',
             'editing/DeleteSelectionCommand.cpp',
+            'editing/DOMSelection.cpp',
+            'editing/DOMSelection.h',
             'editing/EditCommand.cpp',
             'editing/EditingBehavior.cpp',
             'editing/EditingBehavior.h',
@@ -1424,8 +1426,6 @@
             'page/ContextMenuProvider.h',
             'page/CreateWindow.cpp',
             'page/CreateWindow.h',
-            'page/DOMSelection.cpp',
-            'page/DOMSelection.h',
             'page/DOMWindowPagePopup.cpp',
             'page/DOMWindowPagePopup.h',
             'page/DragController.cpp',