Accept text input only if selection has focus.

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

Index: third_party/WebKit/Source/core/editing/SelectionController.cpp
diff --git a/third_party/WebKit/Source/core/editing/SelectionController.cpp b/third_party/WebKit/Source/core/editing/SelectionController.cpp
index 444584d6264a490b8b8483f2cafcc927abd3bc46..59ee5cd465080b80298866392c96c8434bb9a027 100644
--- a/third_party/WebKit/Source/core/editing/SelectionController.cpp
+++ b/third_party/WebKit/Source/core/editing/SelectionController.cpp
@@ -235,9 +235,7 @@ bool SelectionController::HandleSingleClick(
   }
 
   if (visible_pos.IsNull()) {
-    UpdateSelectionForMouseDownDispatchingSelectStart(
-        inner_node, VisibleSelectionInFlatTree(), kCharacterGranularity,
-        HandleVisibility::kNotVisible);
+    Selection().SetSelection(SelectionInFlatTree());

[yosin_UTC9, 2017/05/17 10:26:02]

Do other browser clear selection at clicking user-select:none?

     return false;
   }