arc-bridge: Expose the Mojo version number of the interfaces

components/arc/arc_bridge_service.cc

Index: components/arc/arc_bridge_service.cc
diff --git a/components/arc/arc_bridge_service.cc b/components/arc/arc_bridge_service.cc
index 3c5f391482c31b691da219c83ac3ec743abceacf..475f19e4199d5992d83a09f62b4e1705cf1bc9d9 100644
--- a/components/arc/arc_bridge_service.cc
+++ b/components/arc/arc_bridge_service.cc
@@ -22,7 +22,7 @@ ArcBridgeService* g_arc_bridge_service = nullptr;
 }  // namespace
 
 ArcBridgeService::ArcBridgeService()
-    : available_(false), state_(State::STOPPED) {
+    : available_(false), state_(State::STOPPED), weak_factory_(this) {
   DCHECK(!g_arc_bridge_service);
   g_arc_bridge_service = this;
 }
@@ -58,39 +58,81 @@ void ArcBridgeService::RemoveObserver(Observer* observer) {
 
 void ArcBridgeService::OnAppInstanceReady(AppInstancePtr app_ptr) {
   DCHECK(CalledOnValidThread());
-  app_ptr_ = std::move(app_ptr);
+  temporary_app_ptr_ = std::move(app_ptr);
+  temporary_app_ptr_.QueryVersion(base::Bind(
+      &ArcBridgeService::OnAppVersionReady, weak_factory_.GetWeakPtr()));
+}
+
+void ArcBridgeService::OnAppVersionReady(int32_t version) {
+  DCHECK(CalledOnValidThread());
+  app_ptr_ = std::move(temporary_app_ptr_);
   FOR_EACH_OBSERVER(Observer, observer_list(), OnAppInstanceReady());
 }
 
 void ArcBridgeService::OnInputInstanceReady(InputInstancePtr input_ptr) {
   DCHECK(CalledOnValidThread());
-  input_ptr_ = std::move(input_ptr);
+  temporary_input_ptr_ = std::move(input_ptr);
+  temporary_input_ptr_.QueryVersion(base::Bind(
+      &ArcBridgeService::OnInputVersionReady, weak_factory_.GetWeakPtr()));
+}
+
+void ArcBridgeService::OnInputVersionReady(int32_t version) {
+  DCHECK(CalledOnValidThread());
+  input_ptr_ = std::move(temporary_input_ptr_);
   FOR_EACH_OBSERVER(Observer, observer_list(), OnInputInstanceReady());
 }
 
 void ArcBridgeService::OnNotificationsInstanceReady(
     NotificationsInstancePtr notifications_ptr) {
   DCHECK(CalledOnValidThread());
-  notifications_ptr_ = std::move(notifications_ptr);
+  temporary_notifications_ptr_ = std::move(notifications_ptr);
+  temporary_notifications_ptr_.QueryVersion(
+      base::Bind(&ArcBridgeService::OnNotificationsVersionReady,
+                 weak_factory_.GetWeakPtr()));
+}
+
+void ArcBridgeService::OnNotificationsVersionReady(int32_t version) {
+  DCHECK(CalledOnValidThread());
+  notifications_ptr_ = std::move(temporary_notifications_ptr_);
   FOR_EACH_OBSERVER(Observer, observer_list(), OnNotificationsInstanceReady());
 }
 
 void ArcBridgeService::OnPowerInstanceReady(PowerInstancePtr power_ptr) {
   DCHECK(CalledOnValidThread());
-  power_ptr_ = std::move(power_ptr);
+  temporary_power_ptr_ = std::move(power_ptr);
+  temporary_power_ptr_.QueryVersion(base::Bind(
+      &ArcBridgeService::OnPowerVersionReady, weak_factory_.GetWeakPtr()));
+}
+
+void ArcBridgeService::OnPowerVersionReady(int32_t version) {
+  DCHECK(CalledOnValidThread());
+  power_ptr_ = std::move(temporary_power_ptr_);
   FOR_EACH_OBSERVER(Observer, observer_list(), OnPowerInstanceReady());
 }
 
 void ArcBridgeService::OnProcessInstanceReady(ProcessInstancePtr process_ptr) {
   DCHECK(CalledOnValidThread());
-  process_ptr_ = std::move(process_ptr);
+  temporary_process_ptr_ = std::move(process_ptr);
+  temporary_process_ptr_.QueryVersion(base::Bind(
+      &ArcBridgeService::OnProcessVersionReady, weak_factory_.GetWeakPtr()));
+}
+
+void ArcBridgeService::OnProcessVersionReady(int32_t version) {
+  DCHECK(CalledOnValidThread());
+  process_ptr_ = std::move(temporary_process_ptr_);
   FOR_EACH_OBSERVER(Observer, observer_list(), OnProcessInstanceReady());
 }
 
 void ArcBridgeService::OnSettingsInstanceReady(
     SettingsInstancePtr settings_ptr) {
   DCHECK(CalledOnValidThread());
-  settings_ptr_ = std::move(settings_ptr);
+  temporary_settings_ptr_ = std::move(settings_ptr);
+  temporary_settings_ptr_.QueryVersion(base::Bind(
+      &ArcBridgeService::OnSettingsVersionReady, weak_factory_.GetWeakPtr()));
+}
+
+void ArcBridgeService::OnSettingsVersionReady(int32_t version) {
+  settings_ptr_ = std::move(temporary_settings_ptr_);
   FOR_EACH_OBSERVER(Observer, observer_list(), OnSettingsInstanceReady());
 }