mus: Add EventObserver to allow passively listening to UI events

components/mus/ws/test_utils.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 "components/mus/ws/test_utils.h"
 
 #include "cc/output/copy_output_request.h"
 #include "components/mus/surfaces/surfaces_state.h"
 #include "components/mus/ws/display_binding.h"
 #include "components/mus/ws/window_manager_access_policy.h"
@@ skipping 91 matching lines @@
 
 PlatformDisplay* TestPlatformDisplayFactory::CreatePlatformDisplay() {
   return new TestPlatformDisplay(cursor_id_storage_);
 }
 
 // WindowTreeTestApi  ---------------------------------------------------------
 
 WindowTreeTestApi::WindowTreeTestApi(WindowTree* tree) : tree_(tree) {}
 WindowTreeTestApi::~WindowTreeTestApi() {}
 
+void WindowTreeTestApi::SetEventObserver(mojom::EventMatcherPtr matcher) {
+  tree_->SetEventObserver(std::move(matcher));
+}
+
 // DisplayTestApi  ------------------------------------------------------------
 
 DisplayTestApi::DisplayTestApi(Display* display) : display_(display) {}
 DisplayTestApi::~DisplayTestApi() {}
 
 // EventDispatcherTestApi  ----------------------------------------------------
 
 int EventDispatcherTestApi::NumberPointerTargetsForWindow(
     ServerWindow* window) {
   int count = 0;
@@ skipping 126 matching lines @@
 
 void TestWindowTreeClient::OnWindowSharedPropertyChanged(
     uint32_t window,
     const mojo::String& name,
     mojo::Array<uint8_t> new_data) {
   tracker_.OnWindowSharedPropertyChanged(window, name, std::move(new_data));
 }
 
 void TestWindowTreeClient::OnWindowInputEvent(uint32_t event_id,
                                               uint32_t window,
-                                              mojom::EventPtr event) {
-  tracker_.OnWindowInputEvent(window, std::move(event));
+                                              mojom::EventPtr event,
+                                              bool matched_observer) {
+  tracker_.OnWindowInputEvent(window, std::move(event), matched_observer);
+}
+
+void TestWindowTreeClient::OnEventObserved(mojom::EventPtr event) {
+  tracker_.OnEventObserved(std::move(event));
 }
 
 void TestWindowTreeClient::OnWindowFocused(uint32_t focused_window_id) {
   tracker_.OnWindowFocused(focused_window_id);
 }
 
 void TestWindowTreeClient::OnWindowPredefinedCursorChanged(
     uint32_t window_id,
     mojom::Cursor cursor_id) {
   tracker_.OnWindowPredefinedCursorChanged(window_id, cursor_id);
@@ skipping 93 matching lines @@
     return nullptr;
   if (!tree->AddWindow(parent_client_id, client_window_id))
     return nullptr;
   *client_id = client_window_id;
   return tree->GetWindowByClientId(client_window_id);
 }
 
 }  // namespace test
 }  // namespace ws
 }  // namespace mus