mus: Add watcher for all touch events.

ui/views/mus/window_manager_connection.cc

Index: ui/views/mus/window_manager_connection.cc
diff --git a/ui/views/mus/window_manager_connection.cc b/ui/views/mus/window_manager_connection.cc
index d5f3670520cdf5f3aef280027b0d4184d1b8cbd6..4803f939ca409ebfc3dff9e2e29a9f1451a9d3f2 100644
--- a/ui/views/mus/window_manager_connection.cc
+++ b/ui/views/mus/window_manager_connection.cc
@@ -20,6 +20,7 @@
 #include "ui/views/mus/native_widget_mus.h"
 #include "ui/views/mus/screen_mus.h"
 #include "ui/views/pointer_watcher.h"
+#include "ui/views/touch_event_watcher.h"
 #include "ui/views/views_delegate.h"
 
 namespace views {
@@ -88,7 +89,10 @@ void WindowManagerConnection::AddPointerWatcher(PointerWatcher* watcher) {
     ui::mojom::EventMatcherPtr matcher = ui::mojom::EventMatcher::New();
     matcher->type_matcher = ui::mojom::EventTypeMatcher::New();
     matcher->type_matcher->type = ui::mojom::EventType::POINTER_DOWN;
-    client_->SetEventObserver(std::move(matcher));
+    uint32_t id = client_->AddEventObserver(std::move(matcher));
+    if (id > 0u) {
+      pointer_watcher_observer_id_ = id;
+    }
   }
 }
 
@@ -96,7 +100,30 @@ void WindowManagerConnection::RemovePointerWatcher(PointerWatcher* watcher) {
   pointer_watchers_.RemoveObserver(watcher);
   if (!HasPointerWatcher()) {
     // Last PointerWatcher removed, stop the event observer.
-    client_->SetEventObserver(nullptr);
+    client_->RemoveEventObserver(pointer_watcher_observer_id_);
+  }
+}
+
+void WindowManagerConnection::AddTouchEventWatcher(TouchEventWatcher* watcher) {
+  bool had_watcher = HasTouchEventWatcher();
+  touch_event_watchers_.AddObserver(watcher);
+  if (!had_watcher) {
+    ui::mojom::EventMatcherPtr matcher = ui::mojom::EventMatcher::New();
+    matcher->pointer_kind_matcher = ui::mojom::PointerKindMatcher::New();
+    matcher->pointer_kind_matcher->pointer_kind = ui::mojom::PointerKind::TOUCH;
+    uint32_t id = client_->AddEventObserver(std::move(matcher));
+    if (id > 0u) {
+      touch_event_watcher_observer_id_ = id;
+    }
+  }
+}
+
+void WindowManagerConnection::RemoveTouchEventWatcher(
+  TouchEventWatcher* watcher) {
+  touch_event_watchers_.RemoveObserver(watcher);
+  if (!HasTouchEventWatcher()) {
+    // Last PointerWatcher removed, stop the event observer.
+    client_->RemoveEventObserver(touch_event_watcher_observer_id_);
   }
 }
 
@@ -142,6 +169,15 @@ bool WindowManagerConnection::HasPointerWatcher() {
   return !!iterator.GetNext();
 }
 
+bool WindowManagerConnection::HasTouchEventWatcher() {
+  // Check to see if we really have any observers left. This doesn't use
+  // base::ObserverList<>::might_have_observers() because that returns true
+  // during iteration over the list even when the last observer is removed.
+  base::ObserverList<TouchEventWatcher>::Iterator iterator(
+    &touch_event_watchers_);
+  return !!iterator.GetNext();
+}
+
 void WindowManagerConnection::OnEmbed(ui::Window* root) {}
 
 void WindowManagerConnection::OnDidDestroyClient(ui::WindowTreeClient* client) {
@@ -175,6 +211,14 @@ void WindowManagerConnection::OnEventObserved(const ui::Event& event,
                       OnTouchPressed(*event.AsTouchEvent(), location_in_screen,
                                      target_widget));
   }
+
+  // Receives TouchEvent and TouchPointerEvent
+  if (event.IsTouchEvent() || event.IsTouchPointerEvent()) {
+    FOR_EACH_OBSERVER(TouchEventWatcher, touch_event_watchers_,
+                      OnTouchEventObserved(*event.AsLocatedEvent(),
+                        location_in_screen,
+                        target_widget));
+  }
 }
 
 void WindowManagerConnection::OnWindowManagerFrameValuesChanged() {