Automated rollback of changelist 147799521.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=147812197

src/com/google/javascript/jscomp/NameBasedDefinitionProvider.java

@@ -94,7 +94,7 @@ private boolean jsdocContainsDeclarations(Node node) {
    * should not have to drop definitions itself.
    */
   private void dropUntypedExterns() {
-    for (String externName : nameDefinitionMultimap.keys()) {
+    for (String externName : nameDefinitionMultimap.keySet()) {
       for (Definition def : new ArrayList<Definition>(nameDefinitionMultimap.get(externName))) {
         if (def instanceof ExternalNameOnlyDefinition) {
           Node node = def.getLValue();