Speed up ARC boot if the user launches ARC app while ARC is not ready

chromeos/dbus/session_manager_client.cc

Index: chromeos/dbus/session_manager_client.cc
diff --git a/chromeos/dbus/session_manager_client.cc b/chromeos/dbus/session_manager_client.cc
index c98a7c94ba0b54d2d5dcd005f64e0ff84b1b2e31..f5014125dd1ded8ed27d84486c01a1ce7bde038d 100644
--- a/chromeos/dbus/session_manager_client.cc
+++ b/chromeos/dbus/session_manager_client.cc
@@ -8,6 +8,8 @@
 #include <stdint.h>
 #include <sys/socket.h>
 
+#include <memory>
+
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file_path.h"
@@ -369,6 +371,18 @@ class SessionManagerClientImpl : public SessionManagerClient {
                    login_manager::kSessionManagerStopArcInstance, callback));
   }
 
+  void PrioritizeArcInstance(const ArcCallback& callback) override {
+    dbus::MethodCall method_call(
+        login_manager::kSessionManagerInterface,
+        login_manager::kSessionManagerPrioritizeArcInstance);
+    session_manager_proxy_->CallMethod(
+        &method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::Bind(&SessionManagerClientImpl::OnArcMethod,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   login_manager::kSessionManagerPrioritizeArcInstance,
+                   callback));
+  }
+
   void GetArcStartTime(const GetArcStartTimeCallback& callback) override {
     dbus::MethodCall method_call(
         login_manager::kSessionManagerInterface,
@@ -942,6 +956,10 @@ class SessionManagerClientStubImpl : public SessionManagerClient {
     callback.Run(false);
   }
 
+  void PrioritizeArcInstance(const ArcCallback& callback) override {
+    callback.Run(false);
+  }
+
   void StopArcInstance(const ArcCallback& callback) override {
     callback.Run(false);
   }