Cryptohome: Notify about error in async calls if cryptohome is not ready yet.

chromeos/dbus/cryptohome_client.cc

Index: chromeos/dbus/cryptohome_client.cc
diff --git a/chromeos/dbus/cryptohome_client.cc b/chromeos/dbus/cryptohome_client.cc
index 4ccb11646dbd7567edada63528f285843f67901e..e816b91052eb0e67521d6a6039d92505b6344a07 100644
--- a/chromeos/dbus/cryptohome_client.cc
+++ b/chromeos/dbus/cryptohome_client.cc
@@ -20,6 +20,8 @@
 
 namespace chromeos {
 
+const int CryptohomeClient::kNotReadyAsyncId = -1;
+
 namespace {
 
 // This suffix is appended to user_id to get hash in stub implementation:
@@ -882,8 +884,10 @@ class CryptohomeClientImpl : public CryptohomeClient {
   // Handles the result of AsyncXXX methods.
   void OnAsyncMethodCall(const AsyncMethodCallback& callback,
                          dbus::Response* response) {
-    if (!response)
+    if (!response) {
+      callback.Run(kNotReadyAsyncId);
       return;
+    }
     dbus::MessageReader reader(response);
     int async_id = 0;
     if (!reader.PopInt32(&async_id)) {