Migrate EventRewriterChromeOS to new API (4/n).

This CL rewrites RewriteMouseWheelEvent to use new API.

Bug: 1049489
Test: unit_tests
Change-Id: I97aa14f7b51cd7c5d07125abe74848fa1b445e47
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2055948
Commit-Queue: Yuichiro Hanada <yhanada@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#741685}

chrome/browser/chromeos/events/event_rewriter_unittest.cc

@@ -3211,13 +3211,8 @@ TEST_F(EventRewriterAshTest, MouseWheelEventDispatchImpl) {
 // Tests that if modifier keys are remapped, the flags of a mouse wheel event
 // will be rewritten properly.
 TEST_F(EventRewriterAshTest, MouseWheelEventModifiersRewritten) {
-  // Remap Control to Alt.
-  IntegerPrefMember control;
-  InitModifierKeyPref(&control, prefs::kLanguageRemapControlKeyTo,
-                      ui::chromeos::ModifierKey::kAltKey);
-
   // Generate a mouse wheel event that has a CONTROL_DOWN modifier flag and
-  // expect that it will be rewritten to ALT_DOWN.
+  // expect that no rewriting happens as no modifier remapping is active.
   std::vector<std::unique_ptr<ui::Event>> events;
   gfx::Point location(0, 0);
   ui::MouseWheelEvent positive(
@@ -3229,6 +3224,20 @@ TEST_F(EventRewriterAshTest, MouseWheelEventModifiersRewritten) {
   PopEvents(&events);
   EXPECT_EQ(1u, events.size());
   EXPECT_TRUE(events[0]->IsMouseWheelEvent());
+  EXPECT_TRUE(events[0]->flags() & ui::EF_CONTROL_DOWN);
+
+  // Remap Control to Alt.
+  IntegerPrefMember control;
+  InitModifierKeyPref(&control, prefs::kLanguageRemapControlKeyTo,
+                      ui::chromeos::ModifierKey::kAltKey);
+
+  // Sends the same events once again and expect that it will be rewritten to
+  // ALT_DOWN.
+  details = Send(&positive);
+  ASSERT_FALSE(details.dispatcher_destroyed);
+  PopEvents(&events);
+  EXPECT_EQ(1u, events.size());
+  EXPECT_TRUE(events[0]->IsMouseWheelEvent());
   EXPECT_FALSE(events[0]->flags() & ui::EF_CONTROL_DOWN);
   EXPECT_TRUE(events[0]->flags() & ui::EF_ALT_DOWN);
 }

ui/chromeos/events/event_rewriter_chromeos.cc

@@ -516,6 +516,10 @@ ui::EventDispatchDetails EventRewriterChromeOS::RewriteEvent(
     return RewriteMouseButtonEvent(static_cast<const ui::MouseEvent&>(event),
                                    continuation);
   }
+  if (event.type() == ui::ET_MOUSEWHEEL) {
+    return RewriteMouseWheelEvent(
+        static_cast<const ui::MouseWheelEvent&>(event), continuation);
+  }
   if ((event.type() == ui::ET_TOUCH_PRESSED) ||
       (event.type() == ui::ET_TOUCH_RELEASED)) {
     return RewriteTouchEvent(static_cast<const ui::TouchEvent&>(event),
@@ -541,10 +545,6 @@ ui::EventRewriteStatus EventRewriterChromeOS::RewriteEvent(
                              &status);
     return status;
   }
-  if (event.type() == ui::ET_MOUSEWHEEL) {
-    return RewriteMouseWheelEvent(
-        static_cast<const ui::MouseWheelEvent&>(event), rewritten_event);
-  }
   return ui::EVENT_REWRITE_CONTINUE;
 }
 
@@ -1035,36 +1035,44 @@ ui::EventDispatchDetails EventRewriterChromeOS::RewriteMouseButtonEvent(
   return details;
 }
 
-ui::EventRewriteStatus EventRewriterChromeOS::RewriteMouseWheelEvent(
+// TODO(yhanada): Clean up this method once StickyKeysController migrates to the
+// new API.
+ui::EventDispatchDetails EventRewriterChromeOS::RewriteMouseWheelEvent(
     const ui::MouseWheelEvent& wheel_event,
-    std::unique_ptr<ui::Event>* rewritten_event) {
+    const Continuation continuation) {
   if (!sticky_keys_controller_)
-    return ui::EVENT_REWRITE_CONTINUE;
+    return SendEvent(continuation, &wheel_event);
   int flags = wheel_event.flags();
   RewriteLocatedEvent(wheel_event, &flags);
   auto tmp_event = wheel_event;
   tmp_event.set_flags(flags);
+
+  std::unique_ptr<ui::Event> rewritten_event;
   ui::EventRewriteStatus status =
-      sticky_keys_controller_->RewriteEvent(tmp_event, rewritten_event);
+      sticky_keys_controller_->RewriteEvent(tmp_event, &rewritten_event);
+  // Wheel event shouldn't be discarded.
+  DCHECK_NE(status, ui::EVENT_REWRITE_DISCARD);
 
-  switch (status) {
-    case ui::EVENT_REWRITE_REWRITTEN:
-    case ui::EVENT_REWRITE_DISPATCH_ANOTHER:
-      // whell event has been rewritten and stored in |rewritten_event|.
-      break;
-    case ui::EVENT_REWRITE_CONTINUE:
-      if (flags != wheel_event.flags()) {
-        *rewritten_event = std::make_unique<ui::MouseWheelEvent>(wheel_event);
-        (*rewritten_event)->set_flags(flags);
-        status = ui::EVENT_REWRITE_REWRITTEN;
-      }
-      break;
-    case ui::EVENT_REWRITE_DISCARD:
-      NOTREACHED();
-      break;
+  if (status == ui::EVENT_REWRITE_CONTINUE) {
+    if (flags != wheel_event.flags()) {
+      ui::MouseWheelEvent new_event = wheel_event;
+      new_event.set_flags(flags);
+      return SendEventFinally(continuation, &new_event);
+    }
+    return SendEvent(continuation, &wheel_event);
   }
 
-  return status;
+  ui::EventDispatchDetails details =
+      SendEventFinally(continuation, rewritten_event.get());
+  while (status == ui::EVENT_REWRITE_DISPATCH_ANOTHER &&
+         !details.dispatcher_destroyed) {
+    std::unique_ptr<ui::Event> new_event;
+    status = sticky_keys_controller_->NextDispatchEvent(*rewritten_event,
+                                                        &new_event);
+    details = SendEventFinally(continuation, new_event.get());
+    rewritten_event = std::move(new_event);
+  }
+  return details;
 }
 
 ui::EventDispatchDetails EventRewriterChromeOS::RewriteTouchEvent(

ui/chromeos/events/event_rewriter_chromeos.h

@@ -235,9 +235,9 @@ class EventRewriterChromeOS : public ui::EventRewriter {
   ui::EventDispatchDetails RewriteMouseButtonEvent(
       const ui::MouseEvent& mouse_event,
       const Continuation continuation);
-  ui::EventRewriteStatus RewriteMouseWheelEvent(
+  ui::EventDispatchDetails RewriteMouseWheelEvent(
       const ui::MouseWheelEvent& mouse_event,
-      std::unique_ptr<ui::Event>* rewritten_event);
+      const Continuation continuation);
   ui::EventDispatchDetails RewriteTouchEvent(const ui::TouchEvent& touch_event,
                                              const Continuation continuation);
   ui::EventDispatchDetails RewriteScrollEvent(