Consolidate some more ash tray constants.

ash/common/system/tray/hover_highlight_view.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/common/system/tray/hover_highlight_view.h"
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/system/tray/fixed_sized_image_view.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_popup_utils.h"
@@ skipping 355 matching lines @@
       accessibility_state_ == AccessibilityState::UNCHECKED_CHECKBOX) {
     node_data->role = ui::AX_ROLE_CHECK_BOX;
   }
 
   if (accessibility_state_ == AccessibilityState::CHECKED_CHECKBOX)
     node_data->AddStateFlag(ui::AX_STATE_CHECKED);
 }
 
 gfx::Size HoverHighlightView::GetPreferredSize() const {
   gfx::Size size = ActionableView::GetPreferredSize();
-  const int default_height = GetTrayConstant(TRAY_POPUP_ITEM_MIN_HEIGHT);
 
   if (custom_height_)
     size.set_height(custom_height_);
-  else if (!expandable_ || size.height() < default_height)
-    size.set_height(default_height);
+  else if (!expandable_ || size.height() < kTrayPopupItemMinHeight)
+    size.set_height(kTrayPopupItemMinHeight);
 
   return size;
 }
 
 int HoverHighlightView::GetHeightForWidth(int width) const {
   return GetPreferredSize().height();
 }
 
 void HoverHighlightView::OnMouseEntered(const ui::MouseEvent& event) {
   SetHoverHighlight(true);
@@ skipping 36 matching lines @@
 void HoverHighlightView::OnPaintBackground(gfx::Canvas* canvas) {
   canvas->DrawColor(hover_ ? highlight_color_ : default_color_);
 }
 
 void HoverHighlightView::OnFocus() {
   ScrollRectToVisible(gfx::Rect(gfx::Point(), size()));
   ActionableView::OnFocus();
 }
 
 }  // namespace ash