Generate hashcode on the java types.

editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/SourceChange.java

Index: editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/SourceChange.java
diff --git a/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/SourceChange.java b/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/SourceChange.java
index cc021607f9d684996164dd746653478cd88a6956..6373ef93eeb7b413d043cac957a02b8dfba3c689 100644
--- a/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/SourceChange.java
+++ b/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/generated/types/SourceChange.java
@@ -26,6 +26,7 @@ import com.google.gson.JsonArray;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonPrimitive;
+import org.apache.commons.lang3.builder.HashCodeBuilder;
 import java.util.ArrayList;
 import java.util.Iterator;
 import org.apache.commons.lang3.StringUtils;
@@ -133,6 +134,16 @@ public class SourceChange {
     return selection;
   }
 
+  @Override
+  public int hashCode() {
+    HashCodeBuilder builder = new HashCodeBuilder();
+    builder.append(message);
+    builder.append(edits);
+    builder.append(linkedEditGroups);
+    builder.append(selection);
+    return builder.toHashCode();
+  }
+
   public JsonObject toJson() {
     JsonObject jsonObject = new JsonObject();
     jsonObject.addProperty("message", message);