Use current selection when tab navigation.

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

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 931 matching lines @@
   FrameView* view = frame_->View();
   LayoutViewItem layout_view = frame_->ContentLayoutItem();
 
   if (!view || layout_view.IsNull())
     return LayoutRect();
 
   view->UpdateLifecycleToLayoutClean();
   return LayoutRect(layout_selection_->SelectionBounds());
 }
 
+static IntRect AbsoluteSelectionBoundsOf(
+    const VisibleSelectionInFlatTree& selection) {
+  return ComputeTextRect(
+      EphemeralRangeInFlatTree(selection.Start(), selection.end()));
+}
+
+// TODO(editing-dev): This should be done in FlatTree world.
 void FrameSelection::RevealSelection(const ScrollAlignment& alignment,
                                      RevealExtentOption reveal_extent_option) {
   DCHECK(IsAvailable());
 
   // TODO(editing-dev): The use of updateStyleAndLayoutIgnorePendingStylesheets
   // needs to be audited.  See http://crbug.com/590369 for more details.
   // Calculation of absolute caret bounds requires clean layout.
   GetDocument().UpdateStyleAndLayoutIgnorePendingStylesheets();
 
   LayoutRect rect;
 
   switch (ComputeVisibleSelectionInDOMTree().GetSelectionType()) {
     case kNoSelection:
       return;
     case kCaretSelection:
       rect = LayoutRect(AbsoluteCaretBounds());
       break;
     case kRangeSelection:
-      rect = LayoutRect(reveal_extent_option == kRevealExtent
-                            ? AbsoluteCaretBoundsOf(CreateVisiblePosition(
-                                  ComputeVisibleSelectionInDOMTree().Extent()))
-                            : EnclosingIntRect(UnclippedBounds()));
+      rect = LayoutRect(
+          reveal_extent_option == kRevealExtent
+              ? AbsoluteCaretBoundsOf(CreateVisiblePosition(
+                    ComputeVisibleSelectionInDOMTree().Extent()))
+              : AbsoluteSelectionBoundsOf(ComputeVisibleSelectionInFlatTree()));
       break;
   }
 
   Position start = ComputeVisibleSelectionInDOMTree().Start();
   DCHECK(start.AnchorNode());
   if (start.AnchorNode() && start.AnchorNode()->GetLayoutObject()) {
     // FIXME: This code only handles scrolling the startContainer's layer, but
     // the selection rect could intersect more than just that.
     if (DocumentLoader* document_loader = frame_->Loader().GetDocumentLoader())
       document_loader->GetInitialScrollState().was_scrolled_by_user = true;
@@ skipping 191 matching lines @@
 }
 
 void showTree(const blink::FrameSelection* sel) {
   if (sel)
     sel->ShowTreeForThis();
   else
     LOG(INFO) << "Cannot showTree for <null> FrameSelection.";
 }
 
 #endif