Revert "Add AppWindow.setVisibleOnAllWorkspaces." (https://codereview.chromium.org/469993003)

extensions/shell/browser/shell_native_app_window.cc

 // Copyright 2014 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 "extensions/shell/browser/shell_native_app_window.h"
 
 #include "content/public/browser/web_contents.h"
 #include "ui/aura/window.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/point.h"
@@ skipping 220 matching lines @@
   NOTIMPLEMENTED();
   return gfx::Size();
 }
 
 void ShellNativeAppWindow::SetContentSizeConstraints(
     const gfx::Size& min_size,
     const gfx::Size& max_size) {
   NOTIMPLEMENTED();
 }
 
-void ShellNativeAppWindow::SetVisibleOnAllWorkspaces(bool always_visible) {
-  NOTIMPLEMENTED();
-}
-
 bool ShellNativeAppWindow::CanHaveAlphaEnabled() const {
   NOTIMPLEMENTED();
   return false;
 }
 
 aura::Window* ShellNativeAppWindow::GetWindow() const {
   return app_window_->web_contents()->GetNativeView();
 }
 
 }  // namespace extensions