Add IDLDictionaryBase

third_party/WebKit/Source/core/testing/InternalDictionaryDerivedDerived.idl

Index: third_party/WebKit/Source/core/testing/InternalDictionaryDerivedDerived.idl
diff --git a/ipc/ipc_test.mojom b/third_party/WebKit/Source/core/testing/InternalDictionaryDerivedDerived.idl
similarity index 59%
copy from ipc/ipc_test.mojom
copy to third_party/WebKit/Source/core/testing/InternalDictionaryDerivedDerived.idl
index 9c1b30e2a3a51688acc3f8fe1746e37f430856f5..9635903a55f762a682b79b8048656d6b1678f1ee 100644
--- a/ipc/ipc_test.mojom
+++ b/third_party/WebKit/Source/core/testing/InternalDictionaryDerivedDerived.idl
@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-module IPC.mojom;
-
-interface SimpleTestDriver {
-  ExpectString(string str);
-  RequestQuit() => ();
+dictionary InternalDictionaryDerivedDerived : InternalDictionaryDerived {
+    DOMString derivedDerivedStringMember;
 };