Vertical alignment support for UnifiedSystemTray.

This CL adds right/left shelf alignment support for UnifiedSystemTray.

TEST=PanelLayoutManagerTest.TouchHitTestPanel
(--enable-features=SystemTrayUnified)
BUG=847104

Change-Id: I69d2755dd18d40508c3183ae08a75eef732dcce8
Reviewed-on: https://chromium-review.googlesource.com/1086900Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Tetsui Ohkubo <tetsui@chromium.org>
Cr-Commit-Position: refs/heads/master@{#564907}

ash/system/unified/unified_system_tray.cc

@@ -164,6 +164,7 @@ UnifiedSystemTray::UnifiedSystemTray(Shelf* shelf)
   tray_container()->AddChildView(time_item);
 
   SetInkDropMode(InkDropMode::ON);
+  set_separator_visibility(false);
   SetVisible(true);
 }
 
@@ -223,6 +224,14 @@ void UnifiedSystemTray::ClickedOutsideBubble() {
   CloseBubble();
 }
 
+void UnifiedSystemTray::UpdateAfterShelfAlignmentChange() {
+  TrayBackgroundView::UpdateAfterShelfAlignmentChange();
+  time_view_->UpdateClockLayout(
+      shelf()->IsHorizontalAlignment()
+          ? tray::TimeView::ClockLayout::HORIZONTAL_CLOCK
+          : tray::TimeView::ClockLayout::VERTICAL_CLOCK);
+}
+
 void UnifiedSystemTray::ShowBubbleInternal(bool show_by_click) {
   // Hide volume/brightness slider popup.
   slider_bubble_controller_->CloseBubble();

ash/system/unified/unified_system_tray.h

@@ -54,6 +54,7 @@ class ASH_EXPORT UnifiedSystemTray : public TrayBackgroundView {
   base::string16 GetAccessibleNameForTray() override;
   void HideBubbleWithView(const views::TrayBubbleView* bubble_view) override;
   void ClickedOutsideBubble() override;
+  void UpdateAfterShelfAlignmentChange() override;
 
   UnifiedSystemTrayModel* model() { return model_.get(); }