[chrome.displaySource] Switch mojom targets to use STL types.

extensions/browser/api/display_source/wifi_display/wifi_display_session_service_impl.cc

Index: extensions/browser/api/display_source/wifi_display/wifi_display_session_service_impl.cc
diff --git a/extensions/browser/api/display_source/wifi_display/wifi_display_session_service_impl.cc b/extensions/browser/api/display_source/wifi_display/wifi_display_session_service_impl.cc
index e135093abff529984b804f83930bf6ed731abebb..83cd27b2d4f246ec9798d7e56ccd2b92a87ddc83 100644
--- a/extensions/browser/api/display_source/wifi_display/wifi_display_session_service_impl.cc
+++ b/extensions/browser/api/display_source/wifi_display/wifi_display_session_service_impl.cc
@@ -58,7 +58,7 @@ void WiFiDisplaySessionServiceImpl::SetClient(
 
 void WiFiDisplaySessionServiceImpl::Connect(int32_t sink_id,
                                             int32_t auth_method,
-                                            const mojo::String& auth_data) {
+                                            const std::string& auth_data) {
   DCHECK(client_);
   // We support only one Wi-Fi Display session at a time.
   if (delegate_->connection()) {
@@ -111,7 +111,7 @@ void WiFiDisplaySessionServiceImpl::Disconnect() {
   delegate_->Disconnect(on_error);
 }
 
-void WiFiDisplaySessionServiceImpl::SendMessage(const mojo::String& message) {
+void WiFiDisplaySessionServiceImpl::SendMessage(const std::string& message) {
   if (sink_id_ == DisplaySourceConnectionDelegate::kInvalidSinkId) {
     // The connection might drop before this call has arrived.
     return;