IndexedDB Observers

third_party/WebKit/Source/modules/indexeddb/IDBObserverChanges.idl

Index: third_party/WebKit/Source/modules/indexeddb/IDBObserverChanges.idl
diff --git a/third_party/WebKit/Source/modules/indexeddb/IDBObserverChanges.idl b/third_party/WebKit/Source/modules/indexeddb/IDBObserverChanges.idl
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index 0000000000000000000000000000000000000000..53b3b5506bbbb83fa2f9958a4628f697fd9a225d
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+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// https://github.com/WICG/indexed-db-observers/blob/gh-pages/EXPLAINER.md#changes-argument
+
+[
+   RuntimeEnabled=IDBObserver
+] interface IDBObserverChanges {
+    readonly attribute IDBDatabase database;
+    // Transaction contains the same object stores as the transaction on which IDBTransaction.observe was called.
+    readonly attribute IDBTransaction transaction;
+    // This is the javascript Map<String, sequence<IDBObserverChangesRecord>>,
+    // where the key is the object store name.
+    [CallWith=ScriptState] readonly attribute any records;

[bashi, 2016/06/13 01:35:51]

Can you elaborate why you don't use maplike<DOMString,
sequence<IDBObserverChangesRecord>> ?

[dmurph, 2016/06/13 17:23:52]

Unless the bindings generator we have is different than the spec, you cannot
declare that as a variable type. It's only meant for describing the type that
we're inside. So palak can make a new (dictionary? interface?) type, something
like this:

interface IDBObserverChangesMap {
  maplike<DOMString, sequence<IDBObserverChangesRecord>>;
}

and then use that type as the 'records' attribute type. But the spec doesn't let
you use maplike as a type.

But maybe our system lets you do that? Palak, what happens when you put that
there as the type (not the whole new class, just what bashi suggested).

[palakj1, 2016/06/13 21:30:12]

Indeed, as dmuprh pointed out, I cannot declare maplike<..> as a varialbe type.
I'd need to create a new interface. 

Since IDBObserverChanges won't ever be created by the user, we can ensure what
the type of 'records' is without making it binding in the idl. 
So, would it be fine if I let 'records' be as is for the time being and change
its type to maplike as a part of another patch.

+};
+