Bug 1035056 part 1 - Force CDMProxy to shutdown on tab close or navigation. r=ehsan

content/base/src/nsDocument.cpp

@@ -4299,6 +4299,32 @@ nsDocument::SetScopeObject(nsIGlobalObject* aGlobal)
   }
 }
 
+#ifdef MOZ_EME
+static void
+CheckIfContainsEMEContent(nsISupports* aSupports, void* aContainsEME)
+{
+  nsCOMPtr<nsIDOMHTMLMediaElement> domMediaElem(do_QueryInterface(aSupports));
+  if (domMediaElem) {
+    nsCOMPtr<nsIContent> content(do_QueryInterface(domMediaElem));
+    MOZ_ASSERT(content, "aSupports is not a content");
+    HTMLMediaElement* mediaElem = static_cast<HTMLMediaElement*>(content.get());
+    bool* contains = static_cast<bool*>(aContainsEME);
+    if (mediaElem->GetMediaKeys()) {
+      *contains = true;
+    }
+  }
+}
+
+bool
+nsDocument::ContainsEMEContent()
+{
+  bool containsEME = false;
+  EnumerateActivityObservers(CheckIfContainsEMEContent,
+                             static_cast<void*>(&containsEME));
+  return containsEME;
+}
+#endif // MOZ_EME
+
 static void
 NotifyActivityChanged(nsISupports *aSupports, void *aUnused)
 {
@@ -8456,6 +8482,14 @@ nsDocument::CanSavePresentation(nsIRequest *aNewRequest)
   }
 #endif // MOZ_WEBRTC
 
+#ifdef MOZ_EME
+  // Don't save presentations for documents containing EME content, so that
+  // CDMs reliably shutdown upon user navigation.
+  if (ContainsEMEContent()) {
+    return false;
+  }
+#endif
+
   bool canCache = true;
   if (mSubDocuments)
     PL_DHashTableEnumerate(mSubDocuments, CanCacheSubDocument, &canCache);

content/base/src/nsDocument.h

@@ -1406,6 +1406,10 @@ public:
 
   js::ExpandoAndGeneration mExpandoAndGeneration;
 
+#ifdef MOZ_EME
+  bool ContainsEMEContent();
+#endif
+
 protected:
   already_AddRefed<nsIPresShell> doCreateShell(nsPresContext* aContext,
                                                nsViewManager* aViewManager,

content/html/content/src/HTMLMediaElement.cpp

@@ -3412,6 +3412,20 @@ void HTMLMediaElement::SuspendOrResumeElement(bool aPauseElement, bool aSuspendE
   if (aPauseElement != mPausedForInactiveDocumentOrChannel) {
     mPausedForInactiveDocumentOrChannel = aPauseElement;
     if (aPauseElement) {
+#ifdef MOZ_EME
+      // For EME content, force destruction of the CDM client (and CDM
+      // instance if this is the last client for that CDM instance) and
+      // the CDM's decoder. This ensures the CDM gets reliable and prompt
+      // shutdown notifications, as it may have book-keeping it needs
+      // to do on shutdown.
+      if (mMediaKeys) {
+        mMediaKeys->Shutdown();
+        mMediaKeys = nullptr;
+      }
+      if (mDecoder) {
+        ShutdownDecoder();
+      }
+#endif
       if (mDecoder) {
         mDecoder->Pause();
         mDecoder->Suspend();
@@ -3420,6 +3434,9 @@ void HTMLMediaElement::SuspendOrResumeElement(bool aPauseElement, bool aSuspendE
       }
       mEventDeliveryPaused = aSuspendEvents;
     } else {
+#ifdef MOZ_EME
+      MOZ_ASSERT(!mMediaKeys);
+#endif
       if (mDecoder) {
         mDecoder->Resume(false);
         if (!mPaused && !mDecoder->IsEnded()) {

content/media/eme/CDMProxy.cpp

@@ -39,6 +39,7 @@ void
 CDMProxy::Init(PromiseId aPromiseId)
 {
   MOZ_ASSERT(NS_IsMainThread());
+  NS_ENSURE_TRUE_VOID(!mKeys.IsNull());
 
   nsresult rv = mKeys->GetOrigin(mOrigin);
   if (NS_FAILED(rv)) {
@@ -103,11 +104,10 @@ void
 CDMProxy::OnCDMCreated(uint32_t aPromiseId)
 {
   MOZ_ASSERT(NS_IsMainThread());
-  if (!mKeys.IsNull()) {
-    mKeys->OnCDMCreated(aPromiseId);
-  } else {
-    NS_WARNING("CDMProxy unable to reject promise!");
+  if (mKeys.IsNull()) {
+    return;
   }
+  mKeys->OnCDMCreated(aPromiseId);
 }
 
 void
@@ -323,8 +323,6 @@ CDMProxy::RejectPromise(PromiseId aId, nsresult aCode)
   if (NS_IsMainThread()) {
     if (!mKeys.IsNull()) {
       mKeys->RejectPromise(aId, aCode);
-    } else {
-      NS_WARNING("CDMProxy unable to reject promise!");
     }
   } else {
     nsRefPtr<nsIRunnable> task(new RejectPromiseTask(this, aId, aCode));
@@ -361,6 +359,9 @@ CDMProxy::OnResolveNewSessionPromise(uint32_t aPromiseId,
                                      const nsAString& aSessionId)
 {
   MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
   mKeys->OnSessionCreated(aPromiseId, aSessionId);
 }
 
@@ -370,6 +371,9 @@ CDMProxy::OnSessionMessage(const nsAString& aSessionId,
                            const nsAString& aDestinationURL)
 {
   MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
   nsRefPtr<dom::MediaKeySession> session(mKeys->GetSession(aSessionId));
   if (session) {
     session->DispatchKeyMessage(aMessage, aDestinationURL);
@@ -411,6 +415,9 @@ CDMProxy::OnSessionError(const nsAString& aSessionId,
                          const nsAString& aMsg)
 {
   MOZ_ASSERT(NS_IsMainThread());
+  if (mKeys.IsNull()) {
+    return;
+  }
   nsRefPtr<dom::MediaKeySession> session(mKeys->GetSession(aSessionId));
   if (session) {
     session->DispatchKeyError(aSystemCode);

content/media/eme/MediaKeys.cpp

@@ -54,6 +54,12 @@ RejectPromises(const uint32_t& aKey,
 }
 
 MediaKeys::~MediaKeys()
+{
+  Shutdown();
+}
+
+void
+MediaKeys::Shutdown()
 {
   if (mProxy) {
     mProxy->Shutdown();

content/media/eme/MediaKeys.h

@@ -103,6 +103,8 @@ public:
 
   nsresult GetOrigin(nsString& aOutOrigin);
 
+  void Shutdown();
+
 private:
 
   // Removes promise from mPromises, and returns it.