Fix CannedIDB params

We were passing an extra parameter to this.dump(), but the older
compiler version didn't understand the use of "this" in static
methods, so it didn't catch the mistake.  This removes the extra
parameter.

This was caught by a compiler upgrade.

Issue #2528

Change-Id: I15fcd79dff270bde2dbb35f5da02a9c9a4173407

test/test/util/canned_idb.js

@@ -27,7 +27,7 @@ shaka.test.CannedIDB = class {
    *   database later in a call to restoreJSON().
    */
   static async dumpJSON(name, dummyArrayBuffers) {
-    const savedDatabase = await this.dump(name, dummyArrayBuffers);
+    const savedDatabase = await this.dump(name);
     const replacer =
         (key, value) => this.replacer_(dummyArrayBuffers, key, value);
     return JSON.stringify(savedDatabase, replacer);