Use new downcast helper for blink::PointerEvent

This CL has two goals,
  1. Use To<PointerEvent> and DynamicTo<PointerEvent> as new
     downcast helper
  2. Use IsA<PointerEvent>(element) in place of
     IsPointerEvent(element)

Bug: 891908
Change-Id: I3c7521aefd080d6a7505212a39d0f99c2ea8b2b1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2019746Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Abhijeet Kandalkar <abhijeet@igalia.com>
Cr-Commit-Position: refs/heads/master@{#742489}

third_party/blink/renderer/core/dom/events/event.cc

@@ -273,10 +273,10 @@ void Event::SetTarget(EventTarget* target) {
 }
 
 void Event::SetRelatedTargetIfExists(EventTarget* related_target) {
-  if (auto* event = DynamicTo<MouseEvent>(this)) {
-    event->SetRelatedTarget(related_target);
-  } else if (IsPointerEvent()) {
-    ToPointerEvent(this)->SetRelatedTarget(related_target);
+  if (auto* mouse_event = DynamicTo<MouseEvent>(this)) {
+    mouse_event->SetRelatedTarget(related_target);
+  } else if (auto* pointer_event = DynamicTo<PointerEvent>(this)) {
+    pointer_event->SetRelatedTarget(related_target);
   } else if (auto* focus_event = DynamicTo<FocusEvent>(this)) {
     focus_event->SetRelatedTarget(related_target);
   }

third_party/blink/renderer/core/dom/events/event_target.cc

@@ -180,7 +180,7 @@ void CountFiringEventListeners(const Event& event,
   }
   if (CheckTypeThenUseCount(event, event_type_names::kPointerdown,
                             WebFeature::kPointerDownFired, document)) {
-    if (event.IsPointerEvent() &&
+    if (IsA<PointerEvent>(event) &&
         static_cast<const PointerEvent&>(event).pointerType() == "touch") {
       UseCounter::Count(document, WebFeature::kPointerDownFiredForTouch);
     }

third_party/blink/renderer/core/events/pointer_event.h

@@ -6,6 +6,7 @@
 #define THIRD_PARTY_BLINK_RENDERER_CORE_EVENTS_POINTER_EVENT_H_
 
 #include "third_party/blink/renderer/core/events/mouse_event.h"
+#include "third_party/blink/renderer/platform/wtf/casting.h"
 
 namespace blink {
 
@@ -97,7 +98,10 @@ class CORE_EXPORT PointerEvent final : public MouseEvent {
   HeapVector<Member<PointerEvent>> predicted_events_;
 };
 
-DEFINE_EVENT_TYPE_CASTS(PointerEvent);
+template <>
+struct DowncastTraits<PointerEvent> {
+  static bool AllowFrom(const Event& event) { return event.IsPointerEvent(); }
+};
 
 }  // namespace blink
 

third_party/blink/renderer/core/html/forms/slider_thumb_element.cc

@@ -196,7 +196,7 @@ void SliderThumbElement::StopDragging() {
 }
 
 void SliderThumbElement::DefaultEventHandler(Event& event) {
-  if (event.IsPointerEvent() &&
+  if (IsA<PointerEvent>(event) &&
       event.type() == event_type_names::kLostpointercapture) {
     StopDragging();
     return;

third_party/blink/renderer/core/timing/event_timing.cc

@@ -33,7 +33,7 @@ bool ShouldLogEvent(const Event& event) {
 }
 
 bool IsEventTypeForEventTiming(const Event& event) {
-  return (IsA<MouseEvent>(event) || event.IsPointerEvent() ||
+  return (IsA<MouseEvent>(event) || IsA<PointerEvent>(event) ||
           event.IsTouchEvent() || event.IsKeyboardEvent() ||
           event.IsWheelEvent() || event.IsInputEvent() ||
           event.IsCompositionEvent()) &&
@@ -72,9 +72,10 @@ std::unique_ptr<EventTiming> EventTiming::Create(LocalDOMWindow* window,
   if (!should_report_for_event_timing && !should_log_event)
     return nullptr;
 
+  auto* pointer_event = DynamicTo<PointerEvent>(&event);
   base::TimeTicks event_timestamp =
-      event.IsPointerEvent() ? ToPointerEvent(&event)->OldestPlatformTimeStamp()
-                             : event.PlatformTimeStamp();
+      pointer_event ? pointer_event->OldestPlatformTimeStamp()
+                    : event.PlatformTimeStamp();
 
   base::TimeTicks processing_start = Now();
   if (should_log_event) {

third_party/blink/renderer/modules/media_controls/elements/media_control_timeline_element.cc

@@ -38,8 +38,8 @@ const int kThumbRadius = 6;
 
 // Only respond to main button of primary pointer(s).
 bool IsValidPointerEvent(const blink::Event& event) {
-  DCHECK(event.IsPointerEvent());
-  const blink::PointerEvent& pointer_event = ToPointerEvent(event);
+  DCHECK(blink::IsA<blink::PointerEvent>(event));
+  const auto& pointer_event = blink::To<blink::PointerEvent>(event);
   return pointer_event.isPrimary() &&
          pointer_event.button() ==
              static_cast<int16_t>(blink::WebPointerProperties::Button::kLeft);
@@ -122,7 +122,7 @@ void MediaControlTimelineElement::DefaultEventHandler(Event& event) {
   MediaControlInputElement::DefaultEventHandler(event);
 
   if (IsA<MouseEvent>(event) || event.IsKeyboardEvent() ||
-      event.IsGestureEvent() || event.IsPointerEvent()) {
+      event.IsGestureEvent() || IsA<PointerEvent>(event)) {
     MaybeRecordInteracted();
   }
 

third_party/blink/renderer/modules/media_controls/elements/media_control_volume_slider_element.cc

@@ -8,6 +8,7 @@
 #include "third_party/blink/renderer/core/dom/dom_token_list.h"
 #include "third_party/blink/renderer/core/dom/events/event.h"
 #include "third_party/blink/renderer/core/events/mouse_event.h"
+#include "third_party/blink/renderer/core/events/pointer_event.h"
 #include "third_party/blink/renderer/core/html/media/html_media_element.h"
 #include "third_party/blink/renderer/core/html_names.h"
 #include "third_party/blink/renderer/core/layout/layout_object.h"
@@ -71,7 +72,7 @@ void MediaControlVolumeSliderElement::DefaultEventHandler(Event& event) {
   MediaControlInputElement::DefaultEventHandler(event);
 
   if (IsA<MouseEvent>(event) || event.IsKeyboardEvent() ||
-      event.IsGestureEvent() || event.IsPointerEvent()) {
+      event.IsGestureEvent() || IsA<PointerEvent>(event)) {
     MaybeRecordInteracted();
   }
 

third_party/blink/renderer/modules/media_controls/media_controls_impl.cc

@@ -1696,9 +1696,10 @@ void MediaControlsImpl::ShowCursor() {
 }
 
 bool MediaControlsImpl::ContainsRelatedTarget(Event* event) {
-  if (!event->IsPointerEvent())
+  auto* pointer_event = DynamicTo<PointerEvent>(event);
+  if (!pointer_event)
     return false;
-  EventTarget* related_target = ToPointerEvent(event)->relatedTarget();
+  EventTarget* related_target = pointer_event->relatedTarget();
   if (!related_target)
     return false;
   return contains(related_target->ToNode());

third_party/blink/renderer/modules/xr/xr_canvas_input_provider.cc

@@ -27,7 +27,7 @@ class XRCanvasInputEventListener : public NativeEventListener {
     if (!input_provider_->ShouldProcessEvents())
       return;
 
-    PointerEvent* pointer_event = ToPointerEvent(event);
+    auto* pointer_event = To<PointerEvent>(event);
     DCHECK(pointer_event);
     if (!pointer_event->isPrimary())
       return;