Revert of Update WindowTree::OnWindowInputEventAck to include handled

components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc

Index: components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc
diff --git a/components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc b/components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc
index b82225769b265adc6be3b245e49c830ba1921e52..69c498be0b90b410dfb54bd3f84b40d8e28023a2 100644
--- a/components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc
+++ b/components/mus/public/cpp/tests/window_tree_client_impl_unittest.cc
@@ -27,12 +27,6 @@
 #include "ui/events/event_utils.h"
 #include "ui/gfx/geometry/rect.h"
 
-namespace {
-
-void DoNothingBool(bool result) {}
-
-}  // namespace
-
 namespace mus {
 
 mojo::Array<uint8_t> Int32ToPropertyTransportValue(int32_t value) {
@@ -128,22 +122,21 @@
   void AckEvent() {
     DCHECK(should_manually_ack_);
     DCHECK(!ack_callback_.is_null());
-    ack_callback_.Run(true);
-    ack_callback_ = base::Bind(&::DoNothingBool);
+    ack_callback_.Run();
+    ack_callback_ = base::Closure();
   }
 
   void Reset() {
     received_event_ = false;
-    ack_callback_ = base::Bind(&::DoNothingBool);
+    ack_callback_ = base::Closure();
   }
   bool received_event() const { return received_event_; }
 
  private:
   // InputEventHandler:
-  void OnWindowInputEvent(
-      Window* target,
-      mojom::EventPtr event,
-      scoped_ptr<base::Callback<void(bool)>>* ack_callback) override {
+  void OnWindowInputEvent(Window* target,
+                          mojom::EventPtr event,
+                          scoped_ptr<base::Closure>* ack_callback) override {
     EXPECT_FALSE(received_event_)
         << "Observer was not reset after receiving event.";
     received_event_ = true;
@@ -155,7 +148,7 @@
 
   bool received_event_;
   bool should_manually_ack_;
-  base::Callback<void(bool)> ack_callback_;
+  base::Closure ack_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(TestInputEventHandler);
 };