[MD] replace infobar bottom solid line separator with a shadow.

chrome/browser/ui/views/infobars/infobar_container_view.h

 // Copyright (c) 2011 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_INFOBARS_INFOBAR_CONTAINER_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_INFOBARS_INFOBAR_CONTAINER_VIEW_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "components/infobars/core/infobar_container.h"
 #include "ui/views/accessible_pane_view.h"
 #include "ui/views/view_targeter_delegate.h"
 
 // The views-specific implementation of InfoBarContainer.
 class InfoBarContainerView : public views::AccessiblePaneView,
-                             public infobars::InfoBarContainer,
-                             public views::ViewTargeterDelegate {
+                             public infobars::InfoBarContainer {
  public:
   static const char kViewClassName[];
 
   explicit InfoBarContainerView(Delegate* delegate);
   ~InfoBarContainerView() override;
 
- private:
   // AccessiblePaneView:
   gfx::Size GetPreferredSize() const override;
   const char* GetClassName() const override;
   void Layout() override;
   void GetAccessibleState(ui::AXViewState* state) override;
 
   // InfobarContainer:
   void PlatformSpecificAddInfoBar(infobars::InfoBar* infobar,
                                   size_t position) override;
   void PlatformSpecificRemoveInfoBar(infobars::InfoBar* infobar) override;
 
-  // ViewTargeterDelegate:
-  bool DoesIntersectRect(const View* target,
-                         const gfx::Rect& rect) const override;
+ private:
+  // This view draws the shadow over the web contents below the
+  // lowest infobar. A separate view with a layer is used so it can
+  // draw outside the bounds of |this|.
+  views::View* content_shadow_;
 
   DISALLOW_COPY_AND_ASSIGN(InfoBarContainerView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_INFOBARS_INFOBAR_CONTAINER_VIEW_H_