Makes it so each windowtreeclient can use whatever ids it wants

components/mus/ws/window_tree_host_impl.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 "components/mus/ws/window_tree_host_impl.h"
 
 #include "base/debug/debugger.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/mus/common/types.h"
 #include "components/mus/public/interfaces/input_event_constants.mojom.h"
@@ skipping 231 matching lines @@
     const AddAcceleratorCallback& callback) {
   bool success = event_dispatcher_.AddAccelerator(id, std::move(event_matcher));
   callback.Run(success);
 }
 
 void WindowTreeHostImpl::RemoveAccelerator(uint32_t id) {
   event_dispatcher_.RemoveAccelerator(id);
 }
 
 void WindowTreeHostImpl::AddActivationParent(Id transport_window_id) {
-  ServerWindow* window = connection_manager_->GetWindow(
-      MapWindowIdFromClient(transport_window_id));
+  ServerWindow* window = GetWindowFromWindowTreeHost(transport_window_id);
   if (window)
     activation_parents_.insert(window->id());
 }
 
 void WindowTreeHostImpl::RemoveActivationParent(Id transport_window_id) {
-  ServerWindow* window = connection_manager_->GetWindow(
-      MapWindowIdFromClient(transport_window_id));
+  ServerWindow* window = GetWindowFromWindowTreeHost(transport_window_id);
   if (window)
     activation_parents_.erase(window->id());
 }
 
 void WindowTreeHostImpl::ActivateNextWindow() {
   focus_controller_->ActivateNextWindow();
 }
 
 void WindowTreeHostImpl::SetUnderlaySurfaceOffsetAndExtendedHitArea(
     Id window_id,
     int32_t x_offset,
     int32_t y_offset,
     mojo::InsetsPtr hit_area) {
-  ServerWindow* window =
-      connection_manager_->GetWindow(WindowIdFromTransportId(window_id));
+  ServerWindow* window = GetWindowFromWindowTreeHost(window_id);
   if (!window)
     return;
 
   window->SetUnderlayOffset(gfx::Vector2d(x_offset, y_offset));
   window->set_extended_hit_test_region(hit_area.To<gfx::Insets>());
 }
 
-WindowId WindowTreeHostImpl::MapWindowIdFromClient(
-    Id transport_window_id) const {
-  const WindowTreeImpl* connection = GetWindowTree();
-  return connection ? connection->MapWindowIdFromClient(transport_window_id)
-                    : WindowIdFromTransportId(transport_window_id);
+ServerWindow* WindowTreeHostImpl::GetWindowFromWindowTreeHost(
+    Id transport_window_id) {
+  WindowTreeImpl* connection = GetWindowTree();
+  if (!connection)
+    return nullptr;
+  return connection->GetWindowByClientId(ClientWindowId(transport_window_id));
 }
 
 void WindowTreeHostImpl::OnClientClosed() {
   // |display_manager_.reset()| destroys the display-manager first, and then
   // sets |display_manager_| to nullptr. However, destroying |display_manager_|
   // can destroy the corresponding WindowTreeHostConnection, and |this|. So
   // setting it to nullptr afterwards in reset() ends up writing on free'd
   // memory. So transfer over to a local scoped_ptr<> before destroying it.
   scoped_ptr<DisplayManager> temp = std::move(display_manager_);
 }
@@ skipping 249 matching lines @@
   DispatchInputEventToWindowImpl(target, in_nonclient_area, std::move(event));
 }
 
 void WindowTreeHostImpl::OnWindowDestroyed(ServerWindow* window) {
   windows_needing_frame_destruction_.erase(window);
   window->RemoveObserver(this);
 }
 
 }  // namespace ws
 }  // namespace mus