Make DispatchKeyEventPostIME() asynchronous.

ui/aura/mus/text_input_client_impl.cc

Index: ui/aura/mus/text_input_client_impl.cc
diff --git a/ui/aura/mus/text_input_client_impl.cc b/ui/aura/mus/text_input_client_impl.cc
index 9cc42c4ea4bd06394357b0132ae742cd63cbcc02..68663eec1e9c1676f3032525a54a117fb8482856 100644
--- a/ui/aura/mus/text_input_client_impl.cc
+++ b/ui/aura/mus/text_input_client_impl.cc
@@ -10,8 +10,12 @@
 
 namespace aura {
 
-TextInputClientImpl::TextInputClientImpl(ui::TextInputClient* text_input_client)
-    : text_input_client_(text_input_client), binding_(this) {}
+TextInputClientImpl::TextInputClientImpl(
+    ui::TextInputClient* text_input_client,
+    ui::internal::InputMethodDelegate* delegate)
+    : text_input_client_(text_input_client),
+      binding_(this),
+      delegate_(delegate) {}
 
 TextInputClientImpl::~TextInputClientImpl() {}
 
@@ -43,4 +47,14 @@ void TextInputClientImpl::InsertChar(std::unique_ptr<ui::Event> event) {
   text_input_client_->InsertChar(*event->AsKeyEvent());
 }
 
+void TextInputClientImpl::DispatchKeyEventPostIME(
+    std::unique_ptr<ui::Event> event,
+    const DispatchKeyEventPostIMECallback& callback) {
+  if (delegate_) {
+    delegate_->DispatchKeyEventPostIME(
+        event->AsKeyEvent(),
+        base::MakeUnique<DispatchKeyEventPostIMECallback>(callback));
+  }
+}
+
 }  // namespace aura