Bug 1540136 - P2: CDMProxy stores main thread as nsISerialEventTarget, rather than nsIEventTarget. r=cpearce

This gives us greater flexibility in using the main thread member to run
promises.

The site where we obtain the main thread returns a serial event target, so we're
not doing much more work here, we're just keeping the serial event target
interface, rather than converting to an event target interface.

Differential Revision: https://phabricator.services.mozilla.com/D26205

--HG--
extra : moz-landing-system : lando

dom/media/eme/CDMProxy.h

@@ -82,7 +82,7 @@ class CDMProxy {
   // Main thread only.
   CDMProxy(dom::MediaKeys* aKeys, const nsAString& aKeySystem,
            bool aDistinctiveIdentifierRequired, bool aPersistentStateRequired,
-           nsIEventTarget* aMainThread)
+           nsISerialEventTarget* aMainThread)
       : mKeys(aKeys),
         mKeySystem(aKeySystem),
         mCapabilites("CDMProxy::mCDMCaps"),
@@ -272,7 +272,7 @@ class CDMProxy {
   const bool mPersistentStateRequired;
 
   // The main thread associated with the root document.
-  const nsCOMPtr<nsIEventTarget> mMainThread;
+  const nsCOMPtr<nsISerialEventTarget> mMainThread;
 };
 
 }  // namespace mozilla

dom/media/eme/MediaKeys.cpp

@@ -372,7 +372,7 @@ class MediaKeysGMPCrashHelper : public GMPCrashHelper {
 };
 
 already_AddRefed<CDMProxy> MediaKeys::CreateCDMProxy(
-    nsIEventTarget* aMainThread) {
+    nsISerialEventTarget* aMainThread) {
   EME_LOG("MediaKeys[%p]::CreateCDMProxy()", this);
   RefPtr<CDMProxy> proxy;
 #ifdef MOZ_WIDGET_ANDROID

dom/media/eme/MediaKeys.h

@@ -155,7 +155,7 @@ class MediaKeys final : public nsIDocumentActivity,
   // Instantiate CDMProxy instance.
   // It could be MediaDrmCDMProxy (Widevine on Fennec) or ChromiumCDMProxy (the
   // rest).
-  already_AddRefed<CDMProxy> CreateCDMProxy(nsIEventTarget* aMainThread);
+  already_AddRefed<CDMProxy> CreateCDMProxy(nsISerialEventTarget* aMainThread);
 
   // Removes promise from mPromises, and returns it.
   already_AddRefed<DetailedPromise> RetrievePromise(PromiseId aId);

dom/media/eme/mediadrm/MediaDrmCDMProxy.cpp

@@ -28,7 +28,7 @@ MediaDrmCDMProxy::MediaDrmCDMProxy(dom::MediaKeys* aKeys,
                                    const nsAString& aKeySystem,
                                    bool aDistinctiveIdentifierRequired,
                                    bool aPersistentStateRequired,
-                                   nsIEventTarget* aMainThread)
+                                   nsISerialEventTarget* aMainThread)
     : CDMProxy(aKeys, aKeySystem, aDistinctiveIdentifierRequired,
                aPersistentStateRequired, aMainThread),
       mCDM(nullptr),

dom/media/eme/mediadrm/MediaDrmCDMProxy.h

@@ -31,7 +31,8 @@ class MediaDrmCDMProxy : public CDMProxy {
 
   MediaDrmCDMProxy(dom::MediaKeys* aKeys, const nsAString& aKeySystem,
                    bool aDistinctiveIdentifierRequired,
-                   bool aPersistentStateRequired, nsIEventTarget* aMainThread);
+                   bool aPersistentStateRequired,
+                   nsISerialEventTarget* aMainThread);
 
   void Init(PromiseId aPromiseId, const nsAString& aOrigin,
             const nsAString& aTopLevelOrigin,

dom/media/gmp/ChromiumCDMProxy.cpp

@@ -22,7 +22,7 @@ ChromiumCDMProxy::ChromiumCDMProxy(dom::MediaKeys* aKeys,
                                    GMPCrashHelper* aCrashHelper,
                                    bool aDistinctiveIdentifierRequired,
                                    bool aPersistentStateRequired,
-                                   nsIEventTarget* aMainThread)
+                                   nsISerialEventTarget* aMainThread)
     : CDMProxy(aKeys, aKeySystem, aDistinctiveIdentifierRequired,
                aPersistentStateRequired, aMainThread),
       mCrashHelper(aCrashHelper),

dom/media/gmp/ChromiumCDMProxy.h

@@ -23,7 +23,7 @@ class ChromiumCDMProxy : public CDMProxy {
   ChromiumCDMProxy(dom::MediaKeys* aKeys, const nsAString& aKeySystem,
                    GMPCrashHelper* aCrashHelper,
                    bool aAllowDistinctiveIdentifier, bool aAllowPersistentState,
-                   nsIEventTarget* aMainThread);
+                   nsISerialEventTarget* aMainThread);
 
   void Init(PromiseId aPromiseId, const nsAString& aOrigin,
             const nsAString& aTopLevelOrigin,