Bug 1404230 - Part2 - Add a web api to support HDCP policy check on MediaKeys. r=cpearce,smaug

MozReview-Commit-ID: HW7DtQ6GuOa

--HG--
extra : rebase_source : 27c4fe3845068d979cac1868d0a7cf9262a3e153

dom/media/eme/MediaKeys.cpp

@@ -597,5 +597,37 @@ MediaKeys::GetSessionsInfo(nsString& sessionsInfo)
   }
 }
 
+already_AddRefed<Promise>
+MediaKeys::GetStatusForPolicy(const MediaKeysPolicy& aPolicy,
+                              ErrorResult& aRv)
+{
+  RefPtr<DetailedPromise> promise(MakePromise(aRv,
+    NS_LITERAL_CSTRING("MediaKeys::GetStatusForPolicy()")));
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
+  // Currently, only widevine CDM supports for this API.
+  if (!IsWidevineKeySystem(mKeySystem)) {
+    EME_LOG("MediaKeys[%p]::GetStatusForPolicy() HDCP policy check on unsupported keysystem ", this);
+    NS_WARNING("Tried to query without a CDM");
+    promise->MaybeReject(NS_ERROR_DOM_NOT_SUPPORTED_ERR,
+                         NS_LITERAL_CSTRING("HDCP policy check on unsupported keysystem"));
+    return promise.forget();
+  }
+
+  if (!mProxy) {
+   NS_WARNING("Tried to use a MediaKeys without a CDM");
+   promise->MaybeReject(NS_ERROR_DOM_INVALID_STATE_ERR,
+                        NS_LITERAL_CSTRING("Null CDM in MediaKeys.GetStatusForPolicy()"));
+   return promise.forget();
+  }
+
+  EME_LOG("GetStatusForPolicy minHdcpVersion = %s.", NS_ConvertUTF16toUTF8(aPolicy.mMinHdcpVersion).get());
+  // TODO: Ask CDM to get the real policy.
+  promise->MaybeResolve(MediaKeyStatus::Usable);
+  return promise.forget();
+}
+
 } // namespace dom
 } // namespace mozilla

dom/media/eme/MediaKeys.h

@@ -29,6 +29,7 @@ namespace dom {
 
 class ArrayBufferViewOrArrayBuffer;
 class MediaKeySession;
+struct MediaKeysPolicy;
 class HTMLMediaElement;
 
 typedef nsRefPtrHashtable<nsStringHashKey, MediaKeySession> KeySessionHashMap;
@@ -130,6 +131,10 @@ public:
 
   void GetSessionsInfo(nsString& sessionsInfo);
 
+  // JavaScript: MediaKeys.GetStatusForPolicy()
+  already_AddRefed<Promise> GetStatusForPolicy(const MediaKeysPolicy& aPolicy,
+                                               ErrorResult& aR);
+
 private:
 
   // Instantiate CDMProxy instance.

dom/webidl/MediaKeys.webidl

@@ -18,6 +18,11 @@ enum MediaKeySessionType {
   // persistent-usage-record,
 };
 
+// https://github.com/WICG/media-capabilities/blob/master/eme-extension-policy-check.md
+dictionary MediaKeysPolicy {
+  DOMString minHdcpVersion = "";
+};
+
 interface MediaKeys {
   readonly attribute DOMString keySystem;
 
@@ -26,4 +31,7 @@ interface MediaKeys {
 
   [NewObject]
   Promise<void> setServerCertificate(BufferSource serverCertificate);
+
+  [Pref="media.eme.hdcp-policy-check.enabled", NewObject]
+  Promise<MediaKeyStatus> getStatusForPolicy(optional MediaKeysPolicy policy);
 };