Refactor compositor event handling path to be callback-based

content/renderer/mus/compositor_mus_connection_unittest.cc

Index: content/renderer/mus/compositor_mus_connection_unittest.cc
diff --git a/content/renderer/mus/compositor_mus_connection_unittest.cc b/content/renderer/mus/compositor_mus_connection_unittest.cc
index 6ef2f75dde096b7486f907e92a5a9d7304dae21d..4837e2c6cf0c16169e680e1416b576d60254bfd6 100644
--- a/content/renderer/mus/compositor_mus_connection_unittest.cc
+++ b/content/renderer/mus/compositor_mus_connection_unittest.cc
@@ -79,10 +79,10 @@ class TestInputHandlerManager : public content::InputHandlerManager {
   void SetHandleInputEventResult(content::InputEventAckState result);
 
   // content::InputHandlerManager:
-  content::InputEventAckState HandleInputEvent(
-      int routing_id,
-      const blink::WebInputEvent* input_event,
-      ui::LatencyInfo* latency_info) override;
+  void HandleInputEvent(int routing_id,
+                        ui::ScopedWebInputEvent input_event,
+                        const ui::LatencyInfo& latency_info,
+                        const InputEventAckStateCallback& callback) override;
 
  private:
   // If true content::InputHandlerManager::HandleInputEvent is not called.
@@ -104,14 +104,17 @@ void TestInputHandlerManager::SetHandleInputEventResult(
   result_ = result;
 }
 
-content::InputEventAckState TestInputHandlerManager::HandleInputEvent(
+void TestInputHandlerManager::HandleInputEvent(
     int routing_id,
-    const blink::WebInputEvent* input_event,
-    ui::LatencyInfo* latency_info) {
-  if (override_result_)
-    return result_;
-  return content::InputHandlerManager::HandleInputEvent(routing_id, input_event,
-                                                        latency_info);
+    ui::ScopedWebInputEvent input_event,
+    const ui::LatencyInfo& latency_info,
+    const InputEventAckStateCallback& callback) {
+  if (override_result_) {
+    callback.Run(result_, std::move(input_event), latency_info, nullptr);
+    return;
+  }
+  content::InputHandlerManager::HandleInputEvent(
+      routing_id, std::move(input_event), latency_info, callback);
 }
 
 // Empty implementation of InputHandlerManagerClient.
@@ -422,7 +425,7 @@ TEST_F(CompositorMusConnectionTest, LostAck) {
 }
 
 // Tests that when an input handler consumes the event, that
-// CompositorMusConnection does not consume the ack, nor calls it.
+// CompositorMusConnection will consume the ack, but call as UNHANDLED.
 TEST_F(CompositorMusConnectionTest, InputHandlerConsumes) {
   input_handler_manager()->SetHandleInputEventResult(
       InputEventAckState::INPUT_EVENT_ACK_STATE_CONSUMED);
@@ -435,13 +438,14 @@ TEST_F(CompositorMusConnectionTest, InputHandlerConsumes) {
 
   OnWindowInputEvent(&test_window, *event.get(), &ack_callback);
 
-  EXPECT_TRUE(ack_callback.get());
+  EXPECT_FALSE(ack_callback.get());
   VerifyAndRunQueues(false, false);
-  EXPECT_FALSE(test_callback->called());
+  EXPECT_TRUE(test_callback->called());
+  EXPECT_EQ(EventResult::UNHANDLED, test_callback->result());
 }
 
 // Tests that when the renderer will not ack an event, that
-// CompositorMusConnection does not consume the ack, nor calls it.
+// CompositorMusConnection will consume the ack, but call as UNHANDLED.
 TEST_F(CompositorMusConnectionTest, RendererWillNotSendAck) {
   ui::TestWindow test_window;
   ui::PointerEvent event(
@@ -455,10 +459,11 @@ TEST_F(CompositorMusConnectionTest, RendererWillNotSendAck) {
           base::Bind(&::TestCallback::ResultCallback, test_callback)));
 
   OnWindowInputEvent(&test_window, event, &ack_callback);
-  EXPECT_TRUE(ack_callback.get());
+  EXPECT_FALSE(ack_callback.get());
 
   VerifyAndRunQueues(true, false);
-  EXPECT_FALSE(test_callback->called());
+  EXPECT_TRUE(test_callback->called());
+  EXPECT_EQ(EventResult::UNHANDLED, test_callback->result());
 }
 
 // Tests that when a touch event id provided, that CompositorMusConnection