Cleanup headless templates and message_dispatcher.h.

headless/lib/browser/headless_devtools_client_impl.cc

Index: headless/lib/browser/headless_devtools_client_impl.cc
diff --git a/headless/lib/browser/headless_devtools_client_impl.cc b/headless/lib/browser/headless_devtools_client_impl.cc
index b6e2905a405e8823c552ad6408b1668aa4763412..ff0c2aaca221a468cf0186ce927028ea8a703793 100644
--- a/headless/lib/browser/headless_devtools_client_impl.cc
+++ b/headless/lib/browser/headless_devtools_client_impl.cc
@@ -333,15 +333,6 @@ void HeadlessDevToolsClientImpl::SendMessageWithParams(
   FinalizeAndSendMessage(&message, std::move(callback));
 }
 
-template <typename CallbackType>
-void HeadlessDevToolsClientImpl::SendMessageWithoutParams(
-    const char* method,
-    CallbackType callback) {
-  base::DictionaryValue message;
-  message.SetString("method", method);
-  FinalizeAndSendMessage(&message, std::move(callback));
-}
-
 void HeadlessDevToolsClientImpl::SendMessage(
     const char* method,
     std::unique_ptr<base::Value> params,
@@ -352,21 +343,10 @@ void HeadlessDevToolsClientImpl::SendMessage(
 void HeadlessDevToolsClientImpl::SendMessage(
     const char* method,
     std::unique_ptr<base::Value> params,
-    base::Callback<void()> callback) {
+    base::Closure callback) {
   SendMessageWithParams(method, std::move(params), std::move(callback));
 }
 
-void HeadlessDevToolsClientImpl::SendMessage(
-    const char* method,
-    base::Callback<void(const base::Value&)> callback) {
-  SendMessageWithoutParams(method, std::move(callback));
-}
-
-void HeadlessDevToolsClientImpl::SendMessage(const char* method,
-                                             base::Callback<void()> callback) {
-  SendMessageWithoutParams(method, std::move(callback));
-}
-
 void HeadlessDevToolsClientImpl::RegisterEventHandler(
     const char* method,
     base::Callback<void(const base::Value&)> callback) {
@@ -378,7 +358,7 @@ HeadlessDevToolsClientImpl::Callback::Callback() {}
 
 HeadlessDevToolsClientImpl::Callback::Callback(Callback&& other) = default;
 
-HeadlessDevToolsClientImpl::Callback::Callback(base::Callback<void()> callback)
+HeadlessDevToolsClientImpl::Callback::Callback(base::Closure callback)
     : callback(callback) {}
 
 HeadlessDevToolsClientImpl::Callback::Callback(