Get rid of *live granularity* behavior from selection

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2012 Digia Plc. and/or its subsidiary(-ies)
  * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ skipping 63 matching lines @@
   if (!node || !node->GetLayoutObject())
     return DispatchEventResult::kNotCanceled;
 
   return node->DispatchEvent(
       Event::CreateCancelableBubble(EventTypeNames::selectstart));
 }
 
 VisibleSelectionInFlatTree ExpandSelectionToRespectUserSelectAll(
     Node* target_node,
     const VisibleSelectionInFlatTree& selection) {
+  if (selection.IsNone())
+    return selection;
   Node* const root_user_select_all =
       EditingInFlatTreeStrategy::RootUserSelectAllForNode(target_node);
-  if (!root_user_select_all)
-    return selection;
+  if (!root_user_select_all) {
+    SelectionInFlatTree::Builder builder;
+    if (selection.IsBaseFirst())

[Xiaocheng, 2017/06/23 17:31:11]

Can we use |builder.SetBaseAndExtent(selection.Base(), selection.Extent())|
directly?

[yosin_UTC9, 2017/06/26 04:14:50]

No. When granularity is word/pargraph, base == extent and start/end hold
expanded position.
This is reason why SelectionTemplate::isCaret() is
template <typename Strategy>
bool SelectionTemplate<Strategy>::IsCaret() const {
  return base_.IsNotNull() && base_ == extent_ &&
         granularity_ == kCharacterGranularity;
}

+      builder.SetBaseAndExtent(selection.Start(), selection.End());
+    else
+      builder.SetBaseAndExtent(selection.End(), selection.Start());
+    builder.SetAffinity(selection.Affinity());
+    return CreateVisibleSelection(builder.Build());
+  }
 
   return CreateVisibleSelection(
       SelectionInFlatTree::Builder(selection.AsSelection())
           .Collapse(MostBackwardCaretPosition(
               PositionInFlatTree::BeforeNode(*root_user_select_all),
               kCanCrossEditingBoundary))
           .Extend(MostForwardCaretPosition(
               PositionInFlatTree::AfterNode(*root_user_select_all),
               kCanCrossEditingBoundary))
           .Build());
@@ skipping 1099 matching lines @@
 
 bool IsExtendingSelection(const MouseEventWithHitTestResults& event) {
   bool is_mouse_down_on_link_or_image =
       event.IsOverLink() || event.GetHitTestResult().GetImage();
   return (event.Event().GetModifiers() & WebInputEvent::Modifiers::kShiftKey) !=
              0 &&
          !is_mouse_down_on_link_or_image;
 }
 
 }  // namespace blink