Do not send redundant selectionchange-events (decouple focus)

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

Index: third_party/WebKit/Source/core/editing/LayoutSelection.cpp
diff --git a/third_party/WebKit/Source/core/editing/LayoutSelection.cpp b/third_party/WebKit/Source/core/editing/LayoutSelection.cpp
index 1dccdebda0a3ee1b88a8e1343b95427310c1fd8c..772eaad7f91dc4254325223a36f19fe8f9e3e4dc 100644
--- a/third_party/WebKit/Source/core/editing/LayoutSelection.cpp
+++ b/third_party/WebKit/Source/core/editing/LayoutSelection.cpp
@@ -35,6 +35,7 @@ namespace blink {
 LayoutSelection::LayoutSelection(FrameSelection& frame_selection)
     : frame_selection_(&frame_selection),
       has_pending_selection_(false),
+      force_hide_(false),
       selection_start_(nullptr),
       selection_end_(nullptr),
       selection_start_pos_(-1),
@@ -337,6 +338,14 @@ void LayoutSelection::ClearSelection() {
   SetSelection(0, -1, 0, -1, kPaintInvalidationNewMinusOld);
 }
 
+void LayoutSelection::SetHasPendingSelection(PaintHint hint) {
+  has_pending_selection_ = true;
+  if (hint == PaintHint::kHide)
+    force_hide_ = true;
+  else if (hint == PaintHint::kPaint)
+    force_hide_ = false;
+}
+
 void LayoutSelection::Commit(LayoutView& layout_view) {
   if (!HasPendingSelection())
     return;
@@ -357,7 +366,7 @@ void LayoutSelection::Commit(LayoutView& layout_view) {
   const VisibleSelectionInFlatTree& selection =
       CreateVisibleSelection(CalcVisibleSelection(original_selection));
 
-  if (!selection.IsRange()) {
+  if (!selection.IsRange() || force_hide_) {
     ClearSelection();
     return;
   }
@@ -396,6 +405,7 @@ void LayoutSelection::Commit(LayoutView& layout_view) {
 
 void LayoutSelection::OnDocumentShutdown() {
   has_pending_selection_ = false;
+  force_hide_ = false;
   selection_start_ = nullptr;
   selection_end_ = nullptr;
   selection_start_pos_ = -1;