Adds remainder of support for multiple roots to WS

components/mus/public/cpp/tests/test_window_tree.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/public/cpp/tests/test_window_tree.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mus {
 
-TestWindowTree::TestWindowTree() : got_change_(false), change_id_(0) {}
+TestWindowTree::TestWindowTree()
+    : got_change_(false), change_id_(0), window_id_(0u) {}
 
 TestWindowTree::~TestWindowTree() {}
 
 bool TestWindowTree::GetAndClearChangeId(uint32_t* change_id) {
   if (!got_change_)
     return false;
 
   if (change_id)
     *change_id = change_id_;
   got_change_ = false;
   return true;
 }
 
 bool TestWindowTree::WasEventAcked(uint32_t event_id) const {
   return acked_events_.count(event_id);
 }
 
 void TestWindowTree::NewWindow(
     uint32_t change_id,
     uint32_t window_id,
     mojo::Map<mojo::String, mojo::Array<uint8_t>> properties) {}
 
+void TestWindowTree::NewTopLevelWindow(
+    uint32_t change_id,
+    uint32_t window_id,
+    mojo::Map<mojo::String, mojo::Array<uint8_t>> properties) {
+  got_change_ = true;
+  change_id_ = change_id;
+  window_id_ = window_id;
+}
+
 void TestWindowTree::DeleteWindow(uint32_t change_id, uint32_t window_id) {}
 
 void TestWindowTree::SetWindowBounds(uint32_t change_id,
                                      uint32_t window_id,
                                      mojo::RectPtr bounds) {
   got_change_ = true;
   change_id_ = change_id;
 }
 
 void TestWindowTree::SetClientArea(
@@ skipping 71 matching lines @@
 void TestWindowTree::OnWindowInputEventAck(uint32_t event_id) {
   EXPECT_FALSE(acked_events_.count(event_id));
   acked_events_.insert(event_id);
 }
 
 void TestWindowTree::GetWindowManagerInternalClient(
     mojo::AssociatedInterfaceRequest<mojom::WindowManagerInternalClient>
         internal) {}
 
 }  // namespace mus