Do not send redundant selectionchange-events (decouple focus)

third_party/WebKit/Source/core/page/FocusController.cpp

Index: third_party/WebKit/Source/core/page/FocusController.cpp
diff --git a/third_party/WebKit/Source/core/page/FocusController.cpp b/third_party/WebKit/Source/core/page/FocusController.cpp
index de9da91658722ce16c2e4d1f9ba55da8cf1a3666..079bc6f932f41123f58e1d2cbc9412245dd1aa63 100644
--- a/third_party/WebKit/Source/core/page/FocusController.cpp
+++ b/third_party/WebKit/Source/core/page/FocusController.cpp
@@ -1058,34 +1058,6 @@ static bool relinquishesEditingFocus(const Element& element) {
   return element.document().frame() && rootEditableElement(element);
 }
 
-static void clearSelectionIfNeeded(LocalFrame* oldFocusedFrame,
-                                   LocalFrame* newFocusedFrame,
-                                   Element* newFocusedElement) {
-  if (!oldFocusedFrame || !newFocusedFrame)
-    return;
-
-  if (oldFocusedFrame->document() != newFocusedFrame->document())
-    return;
-
-  FrameSelection& selection = oldFocusedFrame->selection();
-  if (selection.isNone())
-    return;
-
-  Node* selectionStartNode = selection.selection().start().anchorNode();
-  if (selectionStartNode == newFocusedElement ||
-      selectionStartNode->isDescendantOf(newFocusedElement))
-    return;
-
-  if (!enclosingTextControl(selectionStartNode))
-    return;
-
-  if (selectionStartNode->isInShadowTree() &&
-      selectionStartNode->ownerShadowHost() == newFocusedElement)
-    return;
-
-  selection.clear();
-}
-
 bool FocusController::setFocusedElement(Element* element,
                                         Frame* newFocusedFrame) {
   return setFocusedElement(
@@ -1122,10 +1094,6 @@ bool FocusController::setFocusedElement(Element* element,
       newDocument->focusedElement() == element)
     return true;
 
-  if (newFocusedFrame && newFocusedFrame->isLocalFrame())
-    clearSelectionIfNeeded(oldFocusedFrame, toLocalFrame(newFocusedFrame),
-                           element);
-
   if (oldDocument && oldDocument != newDocument)
     oldDocument->clearFocusedElement();