Change MediaKeys.setServerCertificate() to return Promise<boolean>

third_party/WebKit/Source/modules/encryptedmedia/MediaKeys.cpp

 /*
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 62 matching lines @@
     PendingAction(ContentDecryptionModuleResult* result, DOMArrayBuffer* data)
         : m_result(result)
         , m_data(data)
     {
     }
 
     const Member<ContentDecryptionModuleResult> m_result;
     const Member<DOMArrayBuffer> m_data;
 };
 
+// This class wraps the promise resolver used when setting the certificate
+// and is passed to Chromium to fullfill the promise. This implementation of
+// complete() will resolve the promise with true, while completeWithError()
+// will reject the promise with an exception. completeWithSession()
+// is not expected to be called, and will reject the promise.
+class SetCertificateResultPromise : public ContentDecryptionModuleResultPromise {
+public:
+    SetCertificateResultPromise(ScriptState* scriptState)
+        : ContentDecryptionModuleResultPromise(scriptState)
+    {
+    }
+
+    ~SetCertificateResultPromise() override
+    {
+    }
+
+    // ContentDecryptionModuleResult implementation.
+    void complete() override
+    {
+        // TODO(jrummell): The EME spec specifies that "If the Key System
+        // implementation does not support server certificates, return a
+        // promise resolved with false." Need to have chromium return a bool
+        // so that resolving with false is possible. http://crbug.com/618800.
+        resolve(true);

[xhwang, 2016/06/10 21:40:11]

Can we translate completeWithError(NOT_SUPPORTED_ERROR) to resolve(false)? Then
we don't need to really change chromium other than making sure the right
exception is used.

NOT_SUPPORTED_ERROR means "The operation is not supported", which seems
appropriate for this use:

https://www.w3.org/TR/dom/#notsupportederror

[jrummell, 2016/06/10 23:01:15]

Done. I checked all the calls for SetServerCertificate(), and the only one
rejecting with NOT_SUPPORTED_ERROR is in aes_decryptor, so it provides the
desired behavior without lots of changes on the Chromium side.

+    }
+};
+
 MediaKeys* MediaKeys::create(ExecutionContext* context, const WebVector<WebEncryptedMediaSessionType>& supportedSessionTypes, PassOwnPtr<WebContentDecryptionModule> cdm)
 {
     MediaKeys* mediaKeys = new MediaKeys(context, supportedSessionTypes, std::move(cdm));
     mediaKeys->suspendIfNeeded();
     return mediaKeys;
 }
 
 MediaKeys::MediaKeys(ExecutionContext* context, const WebVector<WebEncryptedMediaSessionType>& supportedSessionTypes, PassOwnPtr<WebContentDecryptionModule> cdm)
     : ActiveScriptWrappable(this)
     , ActiveDOMObject(context)
@@ skipping 55 matching lines @@
     // 2. If the keySystem does not support server certificates, return a
     //    promise rejected with a new DOMException whose name is
     //    "NotSupportedError".
     //    (Let the CDM decide whether to support this or not.)
 
     // 3. Let certificate be a copy of the contents of the serverCertificate
     //    parameter.
     DOMArrayBuffer* serverCertificateBuffer = DOMArrayBuffer::create(serverCertificate.data(), serverCertificate.byteLength());
 
     // 4. Let promise be a new promise.
-    SimpleContentDecryptionModuleResultPromise* result = new SimpleContentDecryptionModuleResultPromise(scriptState);
+    SetCertificateResultPromise* result = new SetCertificateResultPromise(scriptState);
     ScriptPromise promise = result->promise();
 
     // 5. Run the following steps asynchronously (documented in timerFired()).
     m_pendingActions.append(PendingAction::CreatePendingSetServerCertificate(result, serverCertificateBuffer));
     if (!m_timer.isActive())
         m_timer.startOneShot(0, BLINK_FROM_HERE);
 
     // 6. Return promise.
     return promise;
 }
@@ skipping 95 matching lines @@
 void MediaKeys::stop()
 {
     ActiveDOMObject::stop();
 
     if (m_timer.isActive())
         m_timer.stop();
     m_pendingActions.clear();
 }
 
 } // namespace blink