ui: ozone: Remove casts from PlatformEvent to ui::Event*

These are no longer necessary since PlatformEvent is now a typedef to
ui::Event*.

BUG=none
TEST=compile

Change-Id: I49749511c7db8d0f2f96add58201ad6d288445f3
Reviewed-on: https://chromium-review.googlesource.com/978468
Commit-Queue: Michael Spang <spang@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545807}

ui/events/ozone/evdev/event_converter_test_util.cc

@@ -110,8 +110,7 @@ class TestEventFactoryEvdev : public EventFactoryEvdev {
   ~TestEventFactoryEvdev() override {}
 
  private:
-  uint32_t DispatchEvent(PlatformEvent platform_event) override {
-    Event* event = static_cast<Event*>(platform_event);
+  uint32_t DispatchEvent(PlatformEvent event) override {
     callback_.Run(event);
     return POST_DISPATCH_NONE;
   }

ui/events/ozone/events_ozone.cc

@@ -9,28 +9,31 @@
 namespace ui {
 
 void DispatchEventFromNativeUiEvent(
-    const PlatformEvent& native_event,
+    const PlatformEvent& event,
     base::OnceCallback<void(ui::Event*)> callback) {
-  ui::Event* native_ui_event = static_cast<ui::Event*>(native_event);
-  if (native_ui_event->IsKeyEvent()) {
-    ui::KeyEvent key_event(native_event);
+  // NB: ui::Events are constructed here using the overload that takes a
+  // const PlatformEvent& (here ui::Event* const&) rather than the copy
+  // constructor. This has side effects and cannot be changed to use the
+  // copy constructor or Event::Clone.
+  if (event->IsKeyEvent()) {
+    ui::KeyEvent key_event(event);
     std::move(callback).Run(&key_event);
-  } else if (native_ui_event->IsMouseWheelEvent()) {
-    ui::MouseWheelEvent wheel_event(native_event);
+  } else if (event->IsMouseWheelEvent()) {
+    ui::MouseWheelEvent wheel_event(event);
     std::move(callback).Run(&wheel_event);
-  } else if (native_ui_event->IsMouseEvent()) {
-    ui::MouseEvent mouse_event(native_event);
+  } else if (event->IsMouseEvent()) {
+    ui::MouseEvent mouse_event(event);
     std::move(callback).Run(&mouse_event);
-  } else if (native_ui_event->IsTouchEvent()) {
-    ui::TouchEvent touch_event(native_event);
+  } else if (event->IsTouchEvent()) {
+    ui::TouchEvent touch_event(event);
     std::move(callback).Run(&touch_event);
-  } else if (native_ui_event->IsScrollEvent()) {
-    ui::ScrollEvent scroll_event(native_event);
+  } else if (event->IsScrollEvent()) {
+    ui::ScrollEvent scroll_event(event);
     std::move(callback).Run(&scroll_event);
-  } else if (native_ui_event->IsGestureEvent()) {
-    std::move(callback).Run(native_ui_event);
+  } else if (event->IsGestureEvent()) {
+    std::move(callback).Run(event);
     // TODO(mohsen): Use the same pattern for scroll/touch/wheel events.
-    // Apparently, there is no need for them to wrap the |native_event|.
+    // Apparently, there is no need for them to wrap the |event|.
   } else {
     NOTREACHED();
   }

ui/ozone/platform/drm/host/drm_window_host.cc

@@ -129,9 +129,8 @@ PlatformImeController* DrmWindowHost::GetPlatformImeController() {
   return nullptr;
 }
 
-bool DrmWindowHost::CanDispatchEvent(const PlatformEvent& ne) {
-  DCHECK(ne);
-  Event* event = static_cast<Event*>(ne);
+bool DrmWindowHost::CanDispatchEvent(const PlatformEvent& event) {
+  DCHECK(event);
 
   // If there is a grab, capture events here.
   gfx::AcceleratedWidget grabber = window_manager_->event_grabber();
@@ -170,10 +169,9 @@ bool DrmWindowHost::CanDispatchEvent(const PlatformEvent& ne) {
   return true;
 }
 
-uint32_t DrmWindowHost::DispatchEvent(const PlatformEvent& native_event) {
-  DCHECK(native_event);
+uint32_t DrmWindowHost::DispatchEvent(const PlatformEvent& event) {
+  DCHECK(event);
 
-  Event* event = static_cast<Event*>(native_event);
   if (event->IsLocatedEvent()) {
     // Make the event location relative to this window's origin.
     LocatedEvent* located_event = event->AsLocatedEvent();
@@ -183,7 +181,7 @@ uint32_t DrmWindowHost::DispatchEvent(const PlatformEvent& native_event) {
     located_event->set_root_location_f(location);
   }
   DispatchEventFromNativeUiEvent(
-      native_event, base::BindOnce(&PlatformWindowDelegate::DispatchEvent,
+      event, base::BindOnce(&PlatformWindowDelegate::DispatchEvent,
                             base::Unretained(delegate_)));
   return POST_DISPATCH_STOP_PROPAGATION;
 }

ui/ozone/platform/wayland/wayland_window.cc

@@ -234,8 +234,7 @@ PlatformImeController* WaylandWindow::GetPlatformImeController() {
   return nullptr;
 }
 
-bool WaylandWindow::CanDispatchEvent(const PlatformEvent& native_event) {
-  Event* event = static_cast<Event*>(native_event);
+bool WaylandWindow::CanDispatchEvent(const PlatformEvent& event) {
   if (event->IsMouseEvent())
     return has_pointer_focus_;
   if (event->IsKeyEvent())

ui/ozone/platform/x11/x11_window_ozone.cc

@@ -69,12 +69,11 @@ bool X11WindowOzone::DispatchXEvent(XEvent* xev) {
   return true;
 }
 
-bool X11WindowOzone::CanDispatchEvent(const PlatformEvent& platform_event) {
+bool X11WindowOzone::CanDispatchEvent(const PlatformEvent& event) {
   return handle_next_event_;
 }
 
-uint32_t X11WindowOzone::DispatchEvent(const PlatformEvent& platform_event) {
-  auto* event = static_cast<Event*>(platform_event);
+uint32_t X11WindowOzone::DispatchEvent(const PlatformEvent& event) {
   if (!window_manager_->event_grabber() ||
       window_manager_->event_grabber() == this) {
     // This is unfortunately needed otherwise events that depend on global state