Create MouseWheelEvent directly instead of through MouseEvent.

BUG=641828
TEST=ash_unittests, unit_tests, blink_converters_unittests,
     events_unittests, exo_unittests, browser_tests

Review-Url: https://codereview.chromium.org/2287403002
Cr-Commit-Position: refs/heads/master@{#415397}

ash/sticky_keys/sticky_keys_unittest.cc

@@ -161,9 +161,16 @@ class StickyKeysTest : public test::AshTestBase {
   // Creates a synthesized MouseEvent that is not backed by a native event.
   ui::MouseEvent* GenerateSynthesizedMouseEventAt(ui::EventType event_type,
                                                   const gfx::Point& location) {
-    ui::MouseEvent* event = new ui::MouseEvent(
-        event_type, location, location, ui::EventTimeForNow(),
-        ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON);
+    ui::MouseEvent* event;
+    if (event_type == ui::ET_MOUSEWHEEL) {
+      event = new ui::MouseWheelEvent(
+          gfx::Vector2d(), location, location, ui::EventTimeForNow(),
+          ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON);
+    } else {
+      event = new ui::MouseEvent(
+          event_type, location, location, ui::EventTimeForNow(),
+          ui::EF_LEFT_MOUSE_BUTTON, ui::EF_LEFT_MOUSE_BUTTON);
+    }
     ui::Event::DispatcherApi dispatcher(event);
     dispatcher.set_target(target_);
     return event;

ash/wm/immersive_fullscreen_controller_unittest.cc

@@ -339,13 +339,7 @@ TEST_F(ImmersiveFullscreenControllerTest, RevealedLock) {
 }
 
 // Test mouse event processing for top-of-screen reveal triggering.
-// TODO: ASan failure happens on ChromeOS (https://crbug.com/641828).
-#if defined(OS_CHROMEOS)
-#define MAYBE_OnMouseEvent DISABLED_OnMouseEvent
-#else
-#define MAYBE_OnMouseEvent OnMouseEvent
-#endif
-TEST_F(ImmersiveFullscreenControllerTest, MAYBE_OnMouseEvent) {
+TEST_F(ImmersiveFullscreenControllerTest, OnMouseEvent) {
   // Set up initial state.
   SetEnabled(true);
   ASSERT_TRUE(controller()->IsEnabled());
@@ -360,8 +354,8 @@ TEST_F(ImmersiveFullscreenControllerTest, MAYBE_OnMouseEvent) {
                           top_container_bounds_in_screen.y());
 
   // Mouse wheel event does nothing.
-  ui::MouseEvent wheel(ui::ET_MOUSEWHEEL, top_edge_pos, top_edge_pos,
-                       ui::EventTimeForNow(), ui::EF_NONE, ui::EF_NONE);
+  ui::MouseWheelEvent wheel(gfx::Vector2d(), top_edge_pos, top_edge_pos,
+                            ui::EventTimeForNow(), ui::EF_NONE, ui::EF_NONE);
   event_generator.Dispatch(&wheel);
   EXPECT_FALSE(top_edge_hover_timer_running());
 

chrome/browser/chromeos/events/event_rewriter_unittest.cc

@@ -2421,10 +2421,10 @@ TEST_F(EventRewriterAshTest, MouseWheelEventDispatchImpl) {
                                ui::DomKey::CONTROL);
   PopEvents(&events);
   gfx::Point location(0, 0);
-  ui::MouseEvent mev(ui::ET_MOUSEWHEEL, location, location,
-                     ui::EventTimeForNow(), ui::EF_LEFT_MOUSE_BUTTON,
-                     ui::EF_LEFT_MOUSE_BUTTON);
-  ui::MouseWheelEvent positive(mev, 0, ui::MouseWheelEvent::kWheelDelta);
+  ui::MouseWheelEvent positive(
+      gfx::Vector2d(0, ui::MouseWheelEvent::kWheelDelta), location, location,
+      ui::EventTimeForNow(), ui::EF_LEFT_MOUSE_BUTTON,
+      ui::EF_LEFT_MOUSE_BUTTON);
   ui::EventDispatchDetails details = Send(&positive);
   ASSERT_FALSE(details.dispatcher_destroyed);
   PopEvents(&events);
@@ -2440,7 +2440,10 @@ TEST_F(EventRewriterAshTest, MouseWheelEventDispatchImpl) {
   SendActivateStickyKeyPattern(ui::VKEY_CONTROL, ui::DomCode::CONTROL_LEFT,
                                ui::DomKey::CONTROL);
   PopEvents(&events);
-  ui::MouseWheelEvent negative(mev, 0, -ui::MouseWheelEvent::kWheelDelta);
+  ui::MouseWheelEvent negative(
+      gfx::Vector2d(0, -ui::MouseWheelEvent::kWheelDelta), location, location,
+      ui::EventTimeForNow(), ui::EF_LEFT_MOUSE_BUTTON,
+      ui::EF_LEFT_MOUSE_BUTTON);
   details = Send(&negative);
   ASSERT_FALSE(details.dispatcher_destroyed);
   PopEvents(&events);
@@ -2464,10 +2467,10 @@ TEST_F(EventRewriterAshTest, MouseWheelEventModifiersRewritten) {
   // expect that it will be rewritten to ALT_DOWN.
   ScopedVector<ui::Event> events;
   gfx::Point location(0, 0);
-  ui::MouseEvent mev(
-      ui::ET_MOUSEWHEEL, location, location, ui::EventTimeForNow(),
-      ui::EF_LEFT_MOUSE_BUTTON | ui::EF_CONTROL_DOWN, ui::EF_LEFT_MOUSE_BUTTON);
-  ui::MouseWheelEvent positive(mev, 0, ui::MouseWheelEvent::kWheelDelta);
+  ui::MouseWheelEvent positive(
+      gfx::Vector2d(0, ui::MouseWheelEvent::kWheelDelta), location, location,
+      ui::EventTimeForNow(), ui::EF_LEFT_MOUSE_BUTTON | ui::EF_CONTROL_DOWN,
+      ui::EF_LEFT_MOUSE_BUTTON);
   ui::EventDispatchDetails details = Send(&positive);
   ASSERT_FALSE(details.dispatcher_destroyed);
   PopEvents(&events);

content/browser/renderer_host/input/synthetic_gesture_target_aura.cc

@@ -66,14 +66,13 @@ void SyntheticGestureTargetAura::DispatchWebTouchEventToPlatform(
 void SyntheticGestureTargetAura::DispatchWebMouseWheelEventToPlatform(
       const blink::WebMouseWheelEvent& web_wheel,
       const ui::LatencyInfo&) {
-  ui::MouseEvent mouse_event(ui::ET_MOUSEWHEEL, gfx::Point(), gfx::Point(),
-                             ui::EventTimeForNow(), ui::EF_NONE, ui::EF_NONE);
+  ui::MouseWheelEvent wheel_event(
+      gfx::Vector2d(web_wheel.deltaX, web_wheel.deltaY), gfx::Point(),
+      gfx::Point(), ui::EventTimeForNow(), ui::EF_NONE, ui::EF_NONE);
   gfx::PointF location(web_wheel.x * device_scale_factor_,
                        web_wheel.y * device_scale_factor_);
-  mouse_event.set_location_f(location);
-  mouse_event.set_root_location_f(location);
-  ui::MouseWheelEvent wheel_event(
-      mouse_event, web_wheel.deltaX, web_wheel.deltaY);
+  wheel_event.set_location_f(location);
+  wheel_event.set_root_location_f(location);
 
   aura::Window* window = GetWindow();
   wheel_event.ConvertLocationToTarget(window, window->GetRootWindow());

mojo/converters/blink/blink_input_events_type_converters_unittest.cc

@@ -43,10 +43,8 @@ TEST(BlinkInputEventsConvertersTest, KeyEvent) {
 TEST(BlinkInputEventsConvertersTest, WheelEvent) {
   const int kDeltaX = 14;
   const int kDeltaY = -3;
-  ui::MouseWheelEvent ui_event(
-      ui::MouseEvent(ui::ET_MOUSEWHEEL, gfx::Point(), gfx::Point(),
-                     base::TimeTicks(), 0, 0),
-      kDeltaX, kDeltaY);
+  ui::MouseWheelEvent ui_event(gfx::Vector2d(kDeltaX, kDeltaY), gfx::Point(),
+                               gfx::Point(), base::TimeTicks(), 0, 0);
   ui::PointerEvent pointer_event(ui_event);
   const std::unique_ptr<blink::WebInputEvent> web_event(
       TypeConverter<std::unique_ptr<blink::WebInputEvent>, ui::Event>::Convert(

ui/events/event.cc

@@ -523,6 +523,7 @@ MouseEvent::MouseEvent(EventType type,
                    flags),
       changed_button_flags_(changed_button_flags),
       pointer_details_(PointerDetails(EventPointerType::POINTER_TYPE_MOUSE)) {
+  DCHECK_NE(ET_MOUSEWHEEL, type);
   latency()->AddLatencyNumber(INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
   if (this->type() == ET_MOUSE_MOVED && IsAnyButton())
     SetType(ET_MOUSE_DRAGGED);
@@ -680,13 +681,18 @@ MouseWheelEvent::MouseWheelEvent(const gfx::Vector2d& offset,
                                  base::TimeTicks time_stamp,
                                  int flags,
                                  int changed_button_flags)
-    : MouseEvent(ui::ET_MOUSEWHEEL,
+    : MouseEvent(ui::ET_UNKNOWN,
                  location,
                  root_location,
                  time_stamp,
                  flags,
                  changed_button_flags),
-      offset_(offset) {}
+      offset_(offset) {
+  // Set event type to ET_UNKNOWN initially in MouseEvent() to pass the
+  // DCHECK for type to enforce that we use MouseWheelEvent() to create
+  // a MouseWheelEvent.
+  SetType(ui::ET_MOUSEWHEEL);
+}
 
 #if defined(OS_WIN)
 // This value matches windows WHEEL_DELTA.

ui/events/event.h

@@ -485,6 +485,7 @@ class EVENTS_EXPORT MouseEvent : public LocatedEvent {
   }
 
   // Used for synthetic events in testing, gesture recognizer and Ozone
+  // Note: Use the ctor for MouseWheelEvent if type is ET_MOUSEWHEEL.
   MouseEvent(EventType type,
              const gfx::Point& location,
              const gfx::Point& root_location,

ui/events/event_unittest.cc

@@ -738,14 +738,17 @@ TEST(EventTest, PointerEventCanConvertFrom) {
 
   // Common mouse events can be converted.
   const EventType mouse_allowed[] = {
-      ET_MOUSE_PRESSED, ET_MOUSE_DRAGGED,         ET_MOUSE_MOVED,
-      ET_MOUSE_ENTERED, ET_MOUSE_EXITED,          ET_MOUSE_RELEASED,
-      ET_MOUSEWHEEL,    ET_MOUSE_CAPTURE_CHANGED,
+      ET_MOUSE_PRESSED,         ET_MOUSE_DRAGGED, ET_MOUSE_MOVED,
+      ET_MOUSE_ENTERED,         ET_MOUSE_EXITED,  ET_MOUSE_RELEASED,
+      ET_MOUSE_CAPTURE_CHANGED,
   };
   for (size_t i = 0; i < arraysize(mouse_allowed); i++) {
     MouseEvent event(mouse_allowed[i], point, point, time, 0, 0);
     EXPECT_TRUE(PointerEvent::CanConvertFrom(event));
   }
+  // Mouse wheel events can be converted.
+  MouseWheelEvent event(gfx::Vector2d(), point, point, time, 0, 0);
+  EXPECT_TRUE(PointerEvent::CanConvertFrom(event));
 
   // Common touch events can be converted.
   const EventType touch_allowed[] = {

ui/events/test/event_generator.cc

@@ -166,9 +166,8 @@ void EventGenerator::ReleaseRightButton() {
 
 void EventGenerator::MoveMouseWheel(int delta_x, int delta_y) {
   gfx::Point location = GetLocationInCurrentRoot();
-  ui::MouseEvent mouseev(ui::ET_MOUSEWHEEL, location, location,
-                         ui::EventTimeForNow(), flags_, 0);
-  ui::MouseWheelEvent wheelev(mouseev, delta_x, delta_y);
+  ui::MouseWheelEvent wheelev(gfx::Vector2d(delta_x, delta_y), location,
+                              location, ui::EventTimeForNow(), flags_, 0);
   Dispatch(&wheelev);
 }