Add PlatformScreenDelegate and start implementation.

services/ui/ws/window_server.cc

Index: services/ui/ws/window_server.cc
diff --git a/services/ui/ws/window_server.cc b/services/ui/ws/window_server.cc
index 5e1128644a673db5bd75d6d322fe4afd7e0a6fbb..02d56c46f37815d4b110ef4a306deb1d1e64fc5e 100644
--- a/services/ui/ws/window_server.cc
+++ b/services/ui/ws/window_server.cc
@@ -37,11 +37,9 @@ struct WindowServer::CurrentMoveLoopState {
   gfx::Rect revert_bounds;
 };
 
-WindowServer::WindowServer(
-    WindowServerDelegate* delegate,
-    const scoped_refptr<ui::SurfacesState>& surfaces_state)
+WindowServer::WindowServer(WindowServerDelegate* delegate)
     : delegate_(delegate),
-      surfaces_state_(surfaces_state),
+      surfaces_state_(new SurfacesState()),
       next_client_id_(1),
       display_manager_(new DisplayManager(this, &user_id_tracker_)),
       current_operation_(nullptr),
@@ -484,6 +482,37 @@ gfx::Rect WindowServer::GetCurrentMoveLoopRevertBounds() {
   return gfx::Rect();
 }
 
+void WindowServer::OnFirstDisplayReady() {
+  delegate_->OnFirstDisplayReady();
+}
+
+void WindowServer::OnNoMoreDisplays() {
+  delegate_->OnNoMoreDisplays();
+}
+
+WindowManagerState* WindowServer::GetWindowManagerStateForUser(
+    const UserId& user_id) {
+  return window_manager_window_tree_factory_set_.GetWindowManagerStateForUser(
+      user_id);
+}
+
+ui::SurfacesState* WindowServer::GetSurfacesState() {
+  return surfaces_state_.get();
+}
+
+bool WindowServer::GetFrameDecorationsForUser(
+    const UserId& user_id,
+    mojom::FrameDecorationValuesPtr* values) {
+  WindowManagerState* window_manager_state =
+      window_manager_window_tree_factory_set_.GetWindowManagerStateForUser(
+          user_id);
+  if (!window_manager_state)
+    return false;
+  if (values && window_manager_state->got_frame_decoration_values())
+    *values = window_manager_state->frame_decoration_values().Clone();
+  return window_manager_state->got_frame_decoration_values();
+}
+
 bool WindowServer::GetAndClearInFlightWindowManagerChange(
     uint32_t window_manager_change_id,
     InFlightWindowManagerChange* change) {
@@ -546,10 +575,6 @@ bool WindowServer::IsUserInHighContrastMode(const UserId& user) const {
   return (iter == high_contrast_mode_.end()) ? false : iter->second;
 }
 
-ui::SurfacesState* WindowServer::GetSurfacesState() {
-  return surfaces_state_.get();
-}
-
 void WindowServer::OnScheduleWindowPaint(ServerWindow* window) {
   if (in_destructor_)
     return;
@@ -739,33 +764,6 @@ void WindowServer::OnTransientWindowRemoved(ServerWindow* window,
   }
 }
 
-void WindowServer::OnFirstDisplayReady() {
-  delegate_->OnFirstDisplayReady();
-}
-
-void WindowServer::OnNoMoreDisplays() {
-  delegate_->OnNoMoreDisplays();
-}
-
-bool WindowServer::GetFrameDecorationsForUser(
-    const UserId& user_id,
-    mojom::FrameDecorationValuesPtr* values) {
-  WindowManagerState* window_manager_state =
-      window_manager_window_tree_factory_set_.GetWindowManagerStateForUser(
-          user_id);
-  if (!window_manager_state)
-    return false;
-  if (values && window_manager_state->got_frame_decoration_values())
-    *values = window_manager_state->frame_decoration_values().Clone();
-  return window_manager_state->got_frame_decoration_values();
-}
-
-WindowManagerState* WindowServer::GetWindowManagerStateForUser(
-    const UserId& user_id) {
-  return window_manager_window_tree_factory_set_.GetWindowManagerStateForUser(
-      user_id);
-}
-
 void WindowServer::OnActiveUserIdChanged(const UserId& previously_active_id,
                                          const UserId& active_id) {
   if (IsUserInHighContrastMode(previously_active_id) ==