CrOS Shelf: Hotseat positioning in overview

Extend the hotseat in overview mode, and hide it in split view mode.

Bug: 1009550, 1009716
Change-Id: I2494c07a2d9bf486ffd4be5a0da4779c855cd59e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1872189Reviewed-by: Alex Newcomer <newcomer@chromium.org>
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707976}

ash/shelf/shelf_layout_manager.cc

@@ -1067,7 +1067,12 @@ HotseatState ShelfLayoutManager::CalculateHotseatState(
             return HotseatState::kShown;
           if (Shell::Get()->overview_controller() &&
               Shell::Get()->overview_controller()->InOverviewSession()) {
-            return HotseatState::kShown;
+            auto* split_view_controller =
+                SplitViewController::Get(Shell::GetPrimaryRootWindow());
+            return split_view_controller &&
+                           split_view_controller->InSplitViewMode()
+                       ? HotseatState::kHidden
+                       : HotseatState::kExtended;
           }
           if (visibility_state == SHELF_AUTO_HIDE) {
             if (auto_hide_state == SHELF_AUTO_HIDE_HIDDEN ||

ash/shelf/shelf_layout_manager_unittest.cc

@@ -3487,7 +3487,7 @@ TEST_P(HotseatShelfLayoutManagerTest, ReleasingSlowDragAboveThreshold) {
 }
 
 // Tests that showing overview after showing the hotseat results in only one
-// animation, to |kShown|.
+// animation, to |kExtended|.
 TEST_P(HotseatShelfLayoutManagerTest, ShowingOverviewFromShownAnimatesOnce) {
   GetPrimaryShelf()->SetAutoHideBehavior(GetParam());
   TabletModeControllerTestApi().EnterTabletMode();
@@ -3508,7 +3508,7 @@ TEST_P(HotseatShelfLayoutManagerTest, ShowingOverviewFromShownAnimatesOnce) {
                                                 .CenterPoint();
   GetEventGenerator()->GestureTapAt(overview_button_center);
 
-  state_watcher_->CheckEqual({HotseatState::kExtended, HotseatState::kShown});
+  state_watcher_->CheckEqual({HotseatState::kExtended});
 }
 
 // Tests that the hotseat is not flush with the bottom of the screen when home