diff -r 000000000000 -r 6474c204b198 mobile/android/base/fxa/login/FxAccountLoginTransition.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/fxa/login/FxAccountLoginTransition.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,68 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.fxa.login;
+
+
+public class FxAccountLoginTransition {
+  public interface Transition {
+  }
+
+  public static class LogMessage implements Transition {
+    public final String detailMessage;
+
+    public LogMessage(String detailMessage) {
+      this.detailMessage = detailMessage;
+    }
+
+    @Override
+    public String toString() {
+      return getClass().getSimpleName() + (this.detailMessage == null ? "" : "('" + this.detailMessage + "')");
+    }
+  }
+
+  public static class AccountNeedsVerification extends LogMessage {
+    public AccountNeedsVerification() {
+      super(null);
+    }
+  }
+
+  public static class AccountVerified extends LogMessage {
+    public AccountVerified() {
+      super(null);
+    }
+  }
+
+  public static class PasswordRequired extends LogMessage {
+    public PasswordRequired() {
+      super(null);
+    }
+  }
+
+  public static class LocalError implements Transition {
+    public final Exception e;
+
+    public LocalError(Exception e) {
+      this.e = e;
+    }
+
+    @Override
+    public String toString() {
+      return "Log(" + this.e + ")";
+    }
+  }
+
+  public static class RemoteError implements Transition {
+    public final Exception e;
+
+    public RemoteError(Exception e) {
+      this.e = e;
+    }
+
+    @Override
+    public String toString() {
+      return "Log(" + (this.e == null ? "null" : this.e) + ")";
+    }
+  }
+}