Add support for X11 workspaces

ui/views/mus/native_widget_mus.cc

 // Copyright 2015 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 "ui/views/mus/native_widget_mus.h"
 
 #include "base/macros.h"
 #include "base/thread_task_runner_handle.h"
 #include "components/mus/public/cpp/property_type_converters.h"
 #include "components/mus/public/cpp/window.h"
@@ skipping 589 matching lines @@
   // not in either state.
   if (IsMinimized() || IsMaximized() || IsFullscreen()) {
     const char* kRestoreBounds_Property =
         mus::mojom::WindowManager::kRestoreBounds_Property;
     if (window_->HasSharedProperty(kRestoreBounds_Property))
       return window_->GetSharedProperty<gfx::Rect>(kRestoreBounds_Property);
   }
   return GetWindowBoundsInScreen();
 }
 
+std::string NativeWidgetMus::GetWorkspace() const {
+  return std::string();
+}
+
 void NativeWidgetMus::SetBounds(const gfx::Rect& bounds) {
   if (!window_tree_host_)
     return;
 
   gfx::Size size(bounds.size());
   const gfx::Size min_size = GetMinimumSize();
   const gfx::Size max_size = GetMaximumSize();
   if (!max_size.IsEmpty())
     size.SetToMin(max_size);
   size.SetToMax(min_size);
@@ skipping 398 matching lines @@
     window_tree_host_->Show();
     GetNativeWindow()->Show();
   } else {
     window_tree_host_->Hide();
     GetNativeWindow()->Hide();
   }
   native_widget_delegate_->OnNativeWidgetVisibilityChanged(window->visible());
 }
 
 }  // namespace views