Refactor AbandonChange code into gerrit-server

While most of the logic for AbandonChange was already in gerrit-server
in ChangeUtil, this change moves it into it's own class.

Using a ReviewResult will allow us to perform one of several related
review actions when responding to an ssh/rpc request and then handle
the result (or more specifically, the errors associated with it) in
a single block of code.

Change-Id: Icb70f2edbb4968a2cc43e78eba71f16f7f93d6e4

gerrit-common/src/main/java/com/google/gerrit/common/data/ReviewResult.java

@@ -0,0 +1,73 @@
+// Copyright (C) 2011 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.common.data;
+
+import com.google.gerrit.reviewdb.Change;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Result from performing a review (comment, abandon, etc.)
+ */
+public class ReviewResult {
+  protected List<Error> errors;
+  protected Change.Id changeId;
+
+  public ReviewResult() {
+    errors = new ArrayList<Error>();
+  }
+
+  public void addError(final Error e) {
+    errors.add(e);
+  }
+
+  public List<Error> getErrors() {
+    return errors;
+  }
+
+  public Change.Id getChangeId() {
+    return changeId;
+  }
+
+  public void setChangeId(Change.Id changeId) {
+    this.changeId = changeId;
+  }
+
+  public static class Error {
+    public static enum Type {
+      /** Not permitted to abandon this change. */
+      ABANDON_NOT_PERMITTED
+    }
+
+    protected Type type;
+
+    protected Error() {
+    }
+
+    public Error(final Type type) {
+      this.type = type;
+    }
+
+    public Type getType() {
+      return type;
+    }
+
+    @Override
+    public String toString() {
+      return type + "";
+    }
+  }
+}