Draw omnibox shadow with a ninebox layer.

chrome/browser/ui/views/omnibox/omnibox_popup_contents_view.h

 // Copyright (c) 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.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_OMNIBOX_OMNIBOX_POPUP_CONTENTS_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_OMNIBOX_OMNIBOX_POPUP_CONTENTS_VIEW_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 40 matching lines @@
   gfx::Rect GetTargetBounds() override;
   void PaintUpdatesNow() override;
   void OnDragCanceled() override;
 
   // gfx::AnimationDelegate:
   void AnimationProgressed(const gfx::Animation* animation) override;
 
   // views::View:
   void Layout() override;
   views::View* GetTooltipHandlerForPoint(const gfx::Point& point) override;
+  void OnBoundsChanged(const gfx::Rect& previous_bounds) override;
   bool OnMousePressed(const ui::MouseEvent& event) override;
   bool OnMouseDragged(const ui::MouseEvent& event) override;
   void OnMouseReleased(const ui::MouseEvent& event) override;
   void OnMouseCaptureLost() override;
   void OnMouseMoved(const ui::MouseEvent& event) override;
   void OnMouseEntered(const ui::MouseEvent& event) override;
   void OnMouseExited(const ui::MouseEvent& event) override;
   void OnGestureEvent(ui::GestureEvent* event) override;
-
+  void ViewHierarchyChanged(
+      const ViewHierarchyChangedDetails& details) override;
+bool experiment_started_ = false;
   bool IsSelectedIndex(size_t index) const;
   bool IsHoveredIndex(size_t index) const;
   gfx::Image GetIconIfExtensionMatch(size_t index) const;
   bool IsStarredMatch(const AutocompleteMatch& match) const;
 
   int max_match_contents_width() const { return max_match_contents_width_; }
 
  protected:
   OmniboxPopupContentsView(const gfx::FontList& font_list,
                            OmniboxView* omnibox_view,
                            OmniboxEditModel* edit_model,
                            LocationBarView* location_bar_view);
   ~OmniboxPopupContentsView() override;
 
   LocationBarView* location_bar_view() { return location_bar_view_; }
 
   // Calculates the height needed to show all the results in the model.
   virtual int CalculatePopupHeight();
   virtual OmniboxResultView* CreateResultView(int model_index,
                                               const gfx::FontList& font_list);
 
  private:
   class AutocompletePopupWidget;
 
   // views::View:
   const char* GetClassName() const override;
-  void OnPaint(gfx::Canvas* canvas) override;
   void PaintChildren(const ui::PaintContext& context) override;
 
   // views::ViewTargeterDelegate:
   views::View* TargetForRect(views::View* root, const gfx::Rect& rect) override;
 
   // Call immediately after construction.
   void Init();
 
   // Returns true if the model has a match at the specified index.
   bool HasMatchAt(size_t index) const;
@@ skipping 27 matching lines @@
   base::WeakPtr<AutocompletePopupWidget> popup_;
 
   // The edit view that invokes us.
   OmniboxView* omnibox_view_;
 
   LocationBarView* location_bar_view_;
 
   // The font list used for result rows, based on the omnibox font list.
   gfx::FontList font_list_;
 
+  // The ninebox layer that draws a drop shadow above and below the popup.
+  std::unique_ptr<ui::Layer> shadow_layer_;
+
   // If the user cancels a dragging action (i.e. by pressing ESC), we don't have
   // a convenient way to release mouse capture. Instead we use this flag to
   // simply ignore all remaining drag events, and the eventual mouse release
   // event. Since OnDragCanceled() can be called when we're not dragging, this
   // flag is reset to false on a mouse pressed event, to make sure we don't
   // erroneously ignore the next drag.
   bool ignore_mouse_drag_;
 
   // The popup sizes vertically using an animation when the popup is getting
   // shorter (not larger, that makes it look "slow").
   gfx::SlideAnimation size_animation_;
   gfx::Rect start_bounds_;
   gfx::Rect target_bounds_;
 
   int start_margin_;
   int end_margin_;
 
   // When the dropdown is not wide enough while displaying postfix suggestions,
   // we use the width of widest match contents to shift the suggestions so that
   // the widest suggestion just reaches the end edge.
   int max_match_contents_width_;
 
   DISALLOW_COPY_AND_ASSIGN(OmniboxPopupContentsView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_OMNIBOX_OMNIBOX_POPUP_CONTENTS_VIEW_H_