Do not send redundant selectionchange-events (decouple focus)

third_party/WebKit/Source/core/editing/commands/EditorCommand.cpp

Index: third_party/WebKit/Source/core/editing/commands/EditorCommand.cpp
diff --git a/third_party/WebKit/Source/core/editing/commands/EditorCommand.cpp b/third_party/WebKit/Source/core/editing/commands/EditorCommand.cpp
index 2f2478ea8995c980aba97a71120a36575bfe5239..1b31e01787c75136961ba864cf9dd9b85a548d18 100644
--- a/third_party/WebKit/Source/core/editing/commands/EditorCommand.cpp
+++ b/third_party/WebKit/Source/core/editing/commands/EditorCommand.cpp
@@ -1888,6 +1888,25 @@ static bool enabledInEditableText(LocalFrame& frame,
   return frame.editor().selectionForCommand(event).rootEditableElement();
 }
 
+static bool enabledInFocusedEditableText(LocalFrame& frame,
+                                         Event* event,
+                                         EditorCommandSource dummy) {
+  if (!enabledInEditableText(frame, event, dummy))
+    return false;
+
+  const Element* const focusedElement = frame.document()->focusedElement();
+  if (!focusedElement->containsIncludingHostElements(
+          *frame.selection()
+               .computeVisibleSelectionInDOMTreeDeprecated()
+               .start()
+               .computeContainerNode())) {
+    // We should not move cursor if selected text does not have focus.
+    return false;
+  }
+
+  return true;
+}
+
 static bool enabledDelete(LocalFrame& frame,
                           Event* event,
                           EditorCommandSource source) {
@@ -2262,7 +2281,7 @@ static const EditorInternalCommand* internalCommand(const String& commandName) {
        enabledVisibleSelection, stateNone, valueNull, notTextInsertion,
        doNotAllowExecutionWhenDisabled},
       {WebEditingCommandType::MoveDown, executeMoveDown,
-       supportedFromMenuOrKeyBinding, enabledInEditableText, stateNone,
+       supportedFromMenuOrKeyBinding, enabledInFocusedEditableText, stateNone,
        valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled},
       {WebEditingCommandType::MoveDownAndModifySelection,
        executeMoveDownAndModifySelection, supportedFromMenuOrKeyBinding,
@@ -2276,7 +2295,7 @@ static const EditorInternalCommand* internalCommand(const String& commandName) {
        enabledVisibleSelection, stateNone, valueNull, notTextInsertion,
        doNotAllowExecutionWhenDisabled},
       {WebEditingCommandType::MoveLeft, executeMoveLeft,
-       supportedFromMenuOrKeyBinding, enabledInEditableText, stateNone,
+       supportedFromMenuOrKeyBinding, enabledInFocusedEditableText, stateNone,
        valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled},
       {WebEditingCommandType::MoveLeftAndModifySelection,
        executeMoveLeftAndModifySelection, supportedFromMenuOrKeyBinding,
@@ -2312,7 +2331,7 @@ static const EditorInternalCommand* internalCommand(const String& commandName) {
        supportedFromMenuOrKeyBinding, enabledVisibleSelection, stateNone,
        valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled},
       {WebEditingCommandType::MoveRight, executeMoveRight,
-       supportedFromMenuOrKeyBinding, enabledInEditableText, stateNone,
+       supportedFromMenuOrKeyBinding, enabledInFocusedEditableText, stateNone,
        valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled},
       {WebEditingCommandType::MoveRightAndModifySelection,
        executeMoveRightAndModifySelection, supportedFromMenuOrKeyBinding,
@@ -2393,7 +2412,7 @@ static const EditorInternalCommand* internalCommand(const String& commandName) {
        supportedFromMenuOrKeyBinding, enabledInEditableText, stateNone,
        valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled},
       {WebEditingCommandType::MoveUp, executeMoveUp,
-       supportedFromMenuOrKeyBinding, enabledInEditableText, stateNone,
+       supportedFromMenuOrKeyBinding, enabledInFocusedEditableText, stateNone,
        valueNull, notTextInsertion, doNotAllowExecutionWhenDisabled},
       {WebEditingCommandType::MoveUpAndModifySelection,
        executeMoveUpAndModifySelection, supportedFromMenuOrKeyBinding,