Add support for emitting iterated inner classes.

src/main/java/com/google/javascript/clutz/DeclarationGenerator.java

@@ -3272,6 +3272,19 @@ void walkInnerSymbols(ObjectType type, String innerNamespace) {
         }
       }
       if (foundNamespaceMembers) emitNamespaceEnd();
+
+      // Recursively repeat the process for inner types of inner types.
+      for (NamedTypePair namedType : innerProps.keySet()) {
+        JSType pType = namedType.type;
+        String qualifiedName = innerNamespace + '.' + namedType.name;
+
+        // This probably could be extended to enums and interfaces, but I rather wait for for some
+        // real world use-cases before supporting what seems like a bad way to organize closure
+        // code.
+        if (isClassLike(pType)) {
+          walkInnerSymbols((FunctionType) pType, qualifiedName);
+        }
+      }
     }
 
     private void visitFunctionExpression(String propName, FunctionType ftype) {

src/test/java/com/google/javascript/clutz/double_inner_class.d.ts

@@ -0,0 +1,24 @@
+declare namespace ಠ_ಠ.clutz {
+  class module$exports$iterated$innerclass {
+    private noStructuralTyping_module$exports$iterated$innerclass : any;
+  }
+}
+declare namespace ಠ_ಠ.clutz.module$exports$iterated$innerclass {
+  class B {
+    private noStructuralTyping_module$exports$iterated$innerclass_B : any;
+  }
+}
+declare namespace ಠ_ಠ.clutz.module$exports$iterated$innerclass.B {
+  class C {
+    private noStructuralTyping_module$exports$iterated$innerclass_B_C : any;
+  }
+}
+declare namespace ಠ_ಠ.clutz.module$exports$iterated$innerclass.B.C {
+  class D {
+    private noStructuralTyping_module$exports$iterated$innerclass_B_C_D : any;
+  }
+}
+declare module 'goog:iterated.innerclass' {
+  import innerclass = ಠ_ಠ.clutz.module$exports$iterated$innerclass;
+  export default innerclass;
+}

src/test/java/com/google/javascript/clutz/double_inner_class.js

@@ -0,0 +1,25 @@
+goog.module('iterated.innerclass');
+
+/**
+ * @struct
+ */
+class A {}
+
+/**
+ * @struct
+ */
+A.B = class {};
+
+/**
+ * @struct
+ */
+A.B.C = class {};
+
+/**
+ * @struct
+ */
+A.B.C.D = class {
+};
+
+
+exports = A;