Do not send redundant selectionchange-events (decouple focus)

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

Index: third_party/WebKit/Source/core/editing/EditingUtilities.cpp
diff --git a/third_party/WebKit/Source/core/editing/EditingUtilities.cpp b/third_party/WebKit/Source/core/editing/EditingUtilities.cpp
index 736d889bf286020e88b7afa6ef2f399bf276d8fd..9e57fe1c6d49c16bd2aa137e8e72712efd4e6f12 100644
--- a/third_party/WebKit/Source/core/editing/EditingUtilities.cpp
+++ b/third_party/WebKit/Source/core/editing/EditingUtilities.cpp
@@ -374,6 +374,29 @@ Element* rootEditableElement(const Node& node) {
   return toElement(const_cast<Node*>(result));
 }
 
+bool selectionHasFocus(const SelectionInFlatTree& selection) {
+  if (selection.isNone())
+    return false;
+
+  const Document* document = selection.base().document();
+  if (!document)

[yosin_UTC9, 2017/03/23 01:26:20]

nit: Since selection.isNone() implies selection.base().document() == nullptr,
we don't need to have this if-statement.

[hugoh_UTC2, 2017/03/23 01:38:06]

Done. See PS27.

+    return false;
+
+  const Element* focus = document->focusedElement();
+  if (!focus) {
+    // No focused element means document root has focus.
+    focus = document->documentElement();
+  }
+
+  const Node* const nodeWhereSelectionStarts =
+      selection.base().computeContainerNode();
+  const Node* const nodeWhereSelectionEnds =
+      selection.extent().computeContainerNode();
+
+  return focus->containsIncludingHostElements(*nodeWhereSelectionStarts) ||
+         focus->containsIncludingHostElements(*nodeWhereSelectionEnds);
+}
+
 ContainerNode* highestEditableRoot(
     const Position& position,
     Element* (*rootEditableElementOf)(const Position&),