Support tooltip for HoverHighlightView

ash/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/system/tray/hover_highlight_view.h"
 
 #include "ash/system/tray/fixed_sized_image_view.h"
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/view_click_listener.h"
 #include "ui/accessibility/ax_view_state.h"
@@ skipping 32 matching lines @@
       hover_(false),
       expandable_(false),
       checkable_(false),
       checked_(false) {
   set_notify_enter_exit_on_child(true);
 }
 
 HoverHighlightView::~HoverHighlightView() {
 }
 
+bool HoverHighlightView::GetTooltipText(const gfx::Point& p,
+                                        base::string16* tooltip) const {
+  if (tooltip_.empty())
+    return false;
+  *tooltip = tooltip_;
+  return true;
+}
+
 void HoverHighlightView::AddIconAndLabel(const gfx::ImageSkia& image,
                                          const base::string16& text,
                                          bool highlight) {
   SetLayoutManager(new views::BoxLayout(
       views::BoxLayout::kHorizontal, 0, 3, kTrayPopupPaddingBetweenItems));
   DoAddIconAndLabel(image, text, highlight);
 }
 
 void HoverHighlightView::AddIndentedIconAndLabel(const gfx::ImageSkia& image,
                                                  const base::string16& text,
@@ skipping 171 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