Unify display ids between Display and PlatformDisplay.

services/ui/ws/display_manager.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 "services/ui/ws/display_manager.h"
 
 #include "base/memory/ptr_util.h"
 #include "services/ui/ws/display.h"
 #include "services/ui/ws/display_manager_delegate.h"
 #include "services/ui/ws/event_dispatcher.h"
 #include "services/ui/ws/server_window.h"
 #include "services/ui/ws/user_display_manager.h"
 #include "services/ui/ws/user_id_tracker.h"
 #include "services/ui/ws/window_manager_state.h"
 
 namespace ui {
 namespace ws {
 
 DisplayManager::DisplayManager(DisplayManagerDelegate* delegate,
                                UserIdTracker* user_id_tracker)
     // |next_root_id_| is used as the lower bits, so that starting at 0 is
     // fine. |next_display_id_| is used by itself, so we start at 1 to reserve
     // 0 as invalid.
     : delegate_(delegate),
       user_id_tracker_(user_id_tracker),
-      next_root_id_(0),
-      next_display_id_(1) {
+      next_root_id_(0) {
   user_id_tracker_->AddObserver(this);
 }
 
 DisplayManager::~DisplayManager() {
   user_id_tracker_->RemoveObserver(this);
   DestroyAllDisplays();
 }
 
 UserDisplayManager* DisplayManager::GetUserDisplayManager(
     const UserId& user_id) {
@@ skipping 84 matching lines @@
           window));
 }
 
 WindowId DisplayManager::GetAndAdvanceNextRootId() {
   // TODO(sky): handle wrapping!
   const uint16_t id = next_root_id_++;
   DCHECK_LT(id, next_root_id_);
   return RootWindowId(id);
 }
 
-uint32_t DisplayManager::GetAndAdvanceNextDisplayId() {
-  // TODO(sky): handle wrapping!
-  const uint32_t id = next_display_id_++;
-  DCHECK_LT(id, next_display_id_);
-  return id;
-}
-
 void DisplayManager::OnDisplayAcceleratedWidgetAvailable(Display* display) {
   DCHECK_NE(0u, pending_displays_.count(display));
   DCHECK_EQ(0u, displays_.count(display));
   const bool is_first_display = displays_.empty();
   displays_.insert(display);
   pending_displays_.erase(display);
   if (is_first_display)
     delegate_->OnFirstDisplayReady();
 }
 
 void DisplayManager::OnActiveUserIdChanged(const UserId& previously_active_id,
                                            const UserId& active_id) {
   WindowManagerState* previous_window_manager_state =
       delegate_->GetWindowManagerStateForUser(previously_active_id);
   gfx::Point mouse_location_on_screen;
   if (previous_window_manager_state) {
     mouse_location_on_screen = previous_window_manager_state->event_dispatcher()
                                    ->mouse_pointer_last_location();
     previous_window_manager_state->Deactivate();
   }
 
   WindowManagerState* current_window_manager_state =
       delegate_->GetWindowManagerStateForUser(active_id);
   if (current_window_manager_state)
     current_window_manager_state->Activate(mouse_location_on_screen);
 }
 
 }  // namespace ws
 }  // namespace ui