WidgetDelegateView is its own contents view.

mash/quick_launch/quick_launch.cc

 // Copyright 2016 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 "mash/quick_launch/quick_launch.h"
 
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_util.h"
@@ skipping 35 matching lines @@
     AddChildView(prompt_);
 
     UpdateEntries();
   }
   ~QuickLaunchUI() override {
     quick_launch_->RemoveWindow(GetWidget());
   }
 
  private:
   // Overridden from views::WidgetDelegate:
-  views::View* GetContentsView() override { return this; }
   base::string16 GetWindowTitle() const override {
     // TODO(beng): use resources.
     return base::ASCIIToUTF16("QuickLaunch");
   }
 
   // Overridden from views::View:
   void Layout() override {
     gfx::Rect bounds = GetLocalBounds();
     bounds.Inset(5, 5);
     prompt_->SetBoundsRect(bounds);
@@ skipping 130 matching lines @@
   windows_.push_back(window);
 }
 
 void QuickLaunch::Create(const shell::Identity& remote_identity,
                          mojom::LaunchableRequest request) {
   bindings_.AddBinding(this, std::move(request));
 }
 
 }  // namespace quick_launch
 }  // namespace mash