Ensure async selections after longpress activate the handles

Fix an issue where the selection handles remain hidden if "empty"
selection updates occur after a longpress but before the nonempty
selection update.

BUG=393025
NOTRY=true

Review URL: https://codereview.chromium.org/1139123009

Cr-Commit-Position: refs/heads/master@{#330190}

2 files changed, 28 insertions, 1 deletions

diff --git a/ui/touch_selection/touch_selection_controller.cc b/ui/touch_selection/touch_selection_controller.cc
index ad010c3..34cc30a 100644
--- a/ui/touch_selection/touch_selection_controller.cc
+++ b/ui/touch_selection/touch_selection_controller.cc
@@ -491,8 +491,14 @@ void TouchSelectionController::DeactivateSelection() {
 }
 
 void TouchSelectionController::ForceNextUpdateIfInactive() {
-  if (active_status_ == INACTIVE)
+  // Only force the update if the reported selection is non-empty but still
+  // considered "inactive", i.e., it wasn't preceded by a user gesture or
+  // the handles have since been explicitly hidden.
+  if (active_status_ == INACTIVE &&
+      start_.type() != SelectionBound::EMPTY &&
+      end_.type() != SelectionBound::EMPTY) {
     force_next_update_ = true;
+  }
 }
 
 gfx::Vector2dF TouchSelectionController::GetStartLineOffset() const {
diff --git a/ui/touch_selection/touch_selection_controller_unittest.cc b/ui/touch_selection/touch_selection_controller_unittest.cc
index c78a5d5..8125c50 100644
--- a/ui/touch_selection/touch_selection_controller_unittest.cc
+++ b/ui/touch_selection/touch_selection_controller_unittest.cc
@@ -575,6 +575,27 @@ TEST_F(TouchSelectionControllerTest, SelectionBasic) {
   EXPECT_EQ(gfx::PointF(), GetLastEventStart());
 }
 
+TEST_F(TouchSelectionControllerTest, SelectionAllowsEmptyUpdateAfterLongPress) {
+  gfx::RectF start_rect(5, 5, 0, 10);
+  gfx::RectF end_rect(50, 5, 0, 10);
+  bool visible = true;
+
+  OnLongPressEvent();
+  EXPECT_THAT(GetAndResetEvents(), IsEmpty());
+
+  // There may be several empty updates after a longpress due to the
+  // asynchronous response. These empty updates should not prevent the selection
+  // handles from (eventually) activating.
+  ClearSelection();
+  EXPECT_THAT(GetAndResetEvents(), IsEmpty());
+
+  ClearSelection();
+  EXPECT_THAT(GetAndResetEvents(), IsEmpty());
+
+  ChangeSelection(start_rect, visible, end_rect, visible);
+  EXPECT_THAT(GetAndResetEvents(), ElementsAre(SELECTION_SHOWN));
+}
+
 TEST_F(TouchSelectionControllerTest, SelectionRepeatedLongPress) {
   gfx::RectF start_rect(5, 5, 0, 10);
   gfx::RectF end_rect(50, 5, 0, 10);