Clean up forward declarations in Source/modules

Source/modules/indexeddb/IDBTransaction.h

Index: Source/modules/indexeddb/IDBTransaction.h
diff --git a/Source/modules/indexeddb/IDBTransaction.h b/Source/modules/indexeddb/IDBTransaction.h
index 426fbffaea842b82ac0811022fe33c8b4305d2d6..976a4c400e9923b2a30c9ff69ba8a9cd79cb3d25 100644
--- a/Source/modules/indexeddb/IDBTransaction.h
+++ b/Source/modules/indexeddb/IDBTransaction.h
@@ -29,21 +29,16 @@
 #include "bindings/core/v8/ScriptState.h"
 #include "core/dom/ActiveDOMObject.h"
 #include "core/dom/DOMError.h"
-#include "core/events/EventListener.h"
-#include "modules/EventModules.h"
 #include "modules/EventTargetModules.h"
 #include "modules/indexeddb/IDBMetadata.h"
 #include "modules/indexeddb/IndexedDB.h"
-#include "platform/heap/Handle.h"
 #include "public/platform/WebIDBDatabase.h"
-#include "public/platform/WebIDBTypes.h"
 #include "wtf/HashSet.h"
 
 namespace blink {
 
 class DOMError;
 class ExceptionState;
-class IDBCursor;
 class IDBDatabase;
 class IDBObjectStore;
 class IDBOpenDBRequest;