Merge branch 'EME-work'

14 files changed, 96 insertions, 3 deletions

diff --git a/dom/base/Navigator.cpp b/dom/base/Navigator.cpp
index 8b20d0196..5c315517c 100644
--- a/dom/base/Navigator.cpp
+++ b/dom/base/Navigator.cpp
@@ -97,8 +97,10 @@
 #endif
 #include "mozilla/dom/ContentChild.h"
 
+#ifdef MOZ_EME
 #include "mozilla/EMEUtils.h"
 #include "mozilla/DetailedPromise.h"
+#endif
 
 namespace mozilla {
 namespace dom {
@@ -214,7 +216,9 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(Navigator)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mServiceWorkerContainer)
 
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mWindow)
+#ifdef MOZ_EME
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMediaKeySystemAccessManager)
+#endif
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPresentation)
 #ifdef MOZ_GAMEPAD
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mGamepadServiceTest)
@@ -288,10 +292,12 @@ Navigator::Invalidate()
 
   mServiceWorkerContainer = nullptr;
 
+#ifdef MOZ_EME
   if (mMediaKeySystemAccessManager) {
     mMediaKeySystemAccessManager->Shutdown();
     mMediaKeySystemAccessManager = nullptr;
   }
+#endif
 
 #ifdef MOZ_GAMEPAD
   if (mGamepadServiceTest) {
@@ -1884,6 +1890,7 @@ Navigator::GetUserAgent(nsPIDOMWindowInner* aWindow, nsIURI* aURI,
   return siteSpecificUA->GetUserAgentForURIAndWindow(aURI, aWindow, aUserAgent);
 }
 
+#ifdef MOZ_EME
 static nsCString
 ToCString(const nsString& aString)
 {
@@ -2009,6 +2016,7 @@ Navigator::RequestMediaKeySystemAccess(const nsAString& aKeySystem,
   mMediaKeySystemAccessManager->Request(promise, aKeySystem, aConfigs);
   return promise.forget();
 }
+#endif
 
 Presentation*
 Navigator::GetPresentation(ErrorResult& aRv)
diff --git a/dom/base/Navigator.h b/dom/base/Navigator.h
index 4b4ae6759..d47a80bc1 100644
--- a/dom/base/Navigator.h
+++ b/dom/base/Navigator.h
@@ -18,7 +18,9 @@
 #include "nsString.h"
 #include "nsTArray.h"
 #include "nsWeakPtr.h"
+#ifdef MOZ_EME
 #include "mozilla/dom/MediaKeySystemAccessManager.h"
+#endif
 
 class nsPluginArray;
 class nsMimeTypeArray;
@@ -258,12 +260,14 @@ public:
   // any, else null.
   static already_AddRefed<nsPIDOMWindowInner> GetWindowFromGlobal(JSObject* aGlobal);
 
+#ifdef MOZ_EME
   already_AddRefed<Promise>
   RequestMediaKeySystemAccess(const nsAString& aKeySystem,
                               const Sequence<MediaKeySystemConfiguration>& aConfig,
                               ErrorResult& aRv);
 private:
   RefPtr<MediaKeySystemAccessManager> mMediaKeySystemAccessManager;
+#endif
 
 public:
   void NotifyVRDisplaysUpdated();
diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index 4926b6c0a..eaea49b02 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -4340,6 +4340,7 @@ nsDocument::SetScopeObject(nsIGlobalObject* aGlobal)
   }
 }
 
+#ifdef MOZ_EME
 static void
 CheckIfContainsEMEContent(nsISupports* aSupports, void* aContainsEME)
 {
@@ -4363,6 +4364,7 @@ nsDocument::ContainsEMEContent()
                              static_cast<void*>(&containsEME));
   return containsEME;
 }
+#endif // MOZ_EME
 
 static void
 CheckIfContainsMSEContent(nsISupports* aSupports, void* aContainsMSE)
@@ -8390,11 +8392,13 @@ 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
 
   // Don't save presentations for documents containing MSE content, to
   // reduce memory usage.
diff --git a/dom/base/nsDocument.h b/dom/base/nsDocument.h
index fc6749c9f..3725b3c18 100644
--- a/dom/base/nsDocument.h
+++ b/dom/base/nsDocument.h
@@ -1267,7 +1267,9 @@ public:
 
   js::ExpandoAndGeneration mExpandoAndGeneration;
 
+#ifdef MOZ_EME
   bool ContainsEMEContent();
+#endif
 
   bool ContainsMSEContent();
 
diff --git a/dom/canvas/CanvasRenderingContext2D.cpp b/dom/canvas/CanvasRenderingContext2D.cpp
index b0a430fe4..35ea2cd1a 100644
--- a/dom/canvas/CanvasRenderingContext2D.cpp
+++ b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -4977,10 +4977,12 @@ CanvasRenderingContext2D::DrawImage(const CanvasImageSource& aImage,
       return;
     }
 
+#ifdef MOZ_EME
     if (video->ContainsRestrictedContent()) {
       aError.Throw(NS_ERROR_NOT_AVAILABLE);
       return;
     }
+#endif
 
     uint16_t readyState;
     if (NS_SUCCEEDED(video->GetReadyState(&readyState)) &&
diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index e81cd20bc..1f1a545fa 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -11,7 +11,9 @@
 #include "mozilla/ArrayUtils.h"
 #include "mozilla/MathAlgorithms.h"
 #include "mozilla/AsyncEventDispatcher.h"
+#ifdef MOZ_EME
 #include "mozilla/dom/MediaEncryptedEvent.h"
+#endif
 
 #include "base/basictypes.h"
 #include "nsIDOMHTMLMediaElement.h"
@@ -820,7 +822,9 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(HTMLMediaElement, nsGenericHTM
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mTextTrackManager)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAudioTrackList)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mVideoTrackList)
+#ifdef MOZ_EME
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMediaKeys)
+#endif
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSelectedVideoStreamTrack)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
@@ -845,7 +849,9 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(HTMLMediaElement, nsGenericHTMLE
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mTextTrackManager)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mAudioTrackList)
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mVideoTrackList)
+#ifdef MOZ_EME
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mMediaKeys)
+#endif
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mSelectedVideoStreamTrack)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
@@ -1020,12 +1026,14 @@ void HTMLMediaElement::ShutdownDecoder()
 
 void HTMLMediaElement::AbortExistingLoads()
 {
+#ifdef MOZ_EME
   // If there is no existing decoder then we don't have anything to
   // report. This prevents reporting the initial load from an
   // empty video element as a failed EME load.
   if (mDecoder) {
     ReportEMETelemetry();
   }
+#endif
   // Abort any already-running instance of the resource selection algorithm.
   mLoadWaitStatus = NOT_WAITING;
 
@@ -1084,7 +1092,9 @@ void HTMLMediaElement::AbortExistingLoads()
   mDownloadSuspendedByCache = false;
   mMediaInfo = MediaInfo();
   mIsEncrypted = false;
+#ifdef MOZ_EME
   mPendingEncryptedInitData.mInitDatas.Clear();
+#endif
   mWaitingForKey = NOT_WAITING_FOR_KEY;
   mSourcePointer = nullptr;
 
@@ -2681,9 +2691,11 @@ HTMLMediaElement::CaptureStreamInternal(bool aFinishWhenEnded,
   if (!window) {
     return nullptr;
   }
+#ifdef MOZ_EME
   if (ContainsRestrictedContent()) {
     return nullptr;
   }
+#endif
 
   if (!mOutputStreams.IsEmpty() &&
       aGraph != mOutputStreams[0].mStream->GetInputStream()->Graph()) {
@@ -3638,6 +3650,7 @@ void HTMLMediaElement::HiddenVideoStop()
   mVideoDecodeSuspendTimer = nullptr;
 }
 
+#ifdef MOZ_EME
 void
 HTMLMediaElement::ReportEMETelemetry()
 {
@@ -3649,6 +3662,7 @@ HTMLMediaElement::ReportEMETelemetry()
                        this, mLoadedDataFired ? "true" : "false"));
   }
 }
+#endif
 
 void
 HTMLMediaElement::ReportTelemetry()
@@ -3997,6 +4011,7 @@ nsresult HTMLMediaElement::FinishDecoderSetup(MediaDecoder* aDecoder,
                               ms.mFinishWhenEnded);
   }
 
+#ifdef MOZ_EME
   if (mMediaKeys) {
     if (mMediaKeys->GetCDMProxy()) {
       mDecoder->SetCDMProxy(mMediaKeys->GetCDMProxy());
@@ -4006,6 +4021,7 @@ nsresult HTMLMediaElement::FinishDecoderSetup(MediaDecoder* aDecoder,
       return NS_ERROR_FAILURE;
     }
   }
+#endif
 
   MediaEventSource<void>* waitingForKeyProducer = mDecoder->WaitingForKeyEvent();
   // Not every decoder will produce waitingForKey events, only add ones that can
@@ -4468,7 +4484,11 @@ void HTMLMediaElement::MetadataLoaded(const MediaInfo* aInfo,
 
   SetMediaInfo(*aInfo);
 
-  mIsEncrypted = aInfo->IsEncrypted() || mPendingEncryptedInitData.IsEncrypted();
+  mIsEncrypted = aInfo->IsEncrypted()
+#ifdef MOZ_EME
+                 || mPendingEncryptedInitData.IsEncrypted()
+#endif
+                 ;
   mTags = aTags.forget();
   mLoadedDataFired = false;
   ChangeReadyState(nsIDOMHTMLMediaElement::HAVE_METADATA);
@@ -4494,11 +4514,13 @@ void HTMLMediaElement::MetadataLoaded(const MediaInfo* aInfo,
       return;
     }
 
+#ifdef MOZ_EME
     // Dispatch a distinct 'encrypted' event for each initData we have.
     for (const auto& initData : mPendingEncryptedInitData.mInitDatas) {
       DispatchEncrypted(initData.mInitData, initData.mType);
     }
     mPendingEncryptedInitData.mInitDatas.Clear();
+#endif
   }
 
   mWatchManager.ManualNotify(&HTMLMediaElement::UpdateReadyStateInternal);
@@ -5431,9 +5453,12 @@ void HTMLMediaElement::SuspendOrResumeElement(bool aPauseElement, bool aSuspendE
     UpdateAudioChannelPlayingState();
     if (aPauseElement) {
       ReportTelemetry();
+#ifdef MOZ_EME
       ReportEMETelemetry();
+#endif
 
-      // For EME content, force destruction of the CDM client (and CDM
+#ifdef MOZ_EME
+      // For EME content, we may 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
@@ -5445,6 +5470,7 @@ void HTMLMediaElement::SuspendOrResumeElement(bool aPauseElement, bool aSuspendE
           ShutdownDecoder();
         }
       }
+#endif
       if (mDecoder) {
         mDecoder->Pause();
         mDecoder->Suspend();
@@ -5495,6 +5521,17 @@ void HTMLMediaElement::NotifyOwnerDocumentActivityChanged()
   bool pauseElement = ShouldElementBePaused();
   SuspendOrResumeElement(pauseElement, !IsActive());
 
+#ifdef MOZ_EME
+  // If the owning document has become inactive we should shutdown the CDM.
+  if (!OwnerDoc()->IsCurrentActiveDocument() && mMediaKeys) {
+      mMediaKeys->Shutdown();
+      mMediaKeys = nullptr;
+      if (mDecoder) {
+        ShutdownDecoder();
+      }
+    }
+#endif
+
   AddRemoveSelfReference();
 }
 
@@ -6270,6 +6307,7 @@ HTMLMediaElement::OnVisibilityChange(Visibility aNewVisibility)
 
 }
 
+#ifdef MOZ_EME
 MediaKeys*
 HTMLMediaElement::GetMediaKeys() const
 {
@@ -6479,6 +6517,7 @@ HTMLMediaElement::GetTopLevelPrincipal()
   principal = doc->NodePrincipal();
   return principal.forget();
 }
+#endif //MOZ_EME
 
 void
 HTMLMediaElement::CannotDecryptWaitingForKey()
diff --git a/dom/html/HTMLMediaElement.h b/dom/html/HTMLMediaElement.h
index d40e9df46..b65049206 100644
--- a/dom/html/HTMLMediaElement.h
+++ b/dom/html/HTMLMediaElement.h
@@ -20,7 +20,9 @@
 #include "mozilla/dom/TextTrackManager.h"
 #include "mozilla/WeakPtr.h"
 #include "MediaDecoder.h"
+#ifdef MOZ_EME
 #include "mozilla/dom/MediaKeys.h"
+#endif
 #include "mozilla/StateWatching.h"
 #include "nsGkAtoms.h"
 #include "PrincipalChangeObserver.h"
@@ -630,6 +632,7 @@ public:
 
   // XPCOM MozPreservesPitch() is OK
 
+#ifdef MOZ_EME
   MediaKeys* GetMediaKeys() const;
 
   already_AddRefed<Promise> SetMediaKeys(MediaKeys* mediaKeys,
@@ -651,6 +654,7 @@ public:
   already_AddRefed<nsIPrincipal> GetTopLevelPrincipal();
 
   bool ContainsRestrictedContent();
+#endif // MOZ_EME
 
   void CannotDecryptWaitingForKey();
 
@@ -1198,7 +1202,9 @@ protected:
    */
   void HiddenVideoStop();
 
+#ifdef MOZ_EME
   void ReportEMETelemetry();
+#endif
 
   void ReportTelemetry();
 
@@ -1471,8 +1477,10 @@ protected:
   // Timer used to simulate video-suspend.
   nsCOMPtr<nsITimer> mVideoDecodeSuspendTimer;
 
+#ifdef MOZ_EME
   // Encrypted Media Extension media keys.
   RefPtr<MediaKeys> mMediaKeys;
+#endif
 
   // Stores the time at the start of the current 'played' range.
   double mCurrentPlayRangeStart;
@@ -1627,8 +1635,10 @@ protected:
   // Listens for waitingForKey events from the owned decoder.
   MediaEventListener mWaitingForKeyListener;
 
+#ifdef MOZ_EME
   // Init Data that needs to be sent in 'encrypted' events in MetadataLoaded().
   EncryptionInfo mPendingEncryptedInitData;
+#endif
 
   // True if the media's channel's download has been suspended.
   Watchable<bool> mDownloadSuspendedByCache;
diff --git a/dom/media/MediaDecoderOwner.h b/dom/media/MediaDecoderOwner.h
index f884686fb..f993b4324 100644
--- a/dom/media/MediaDecoderOwner.h
+++ b/dom/media/MediaDecoderOwner.h
@@ -143,11 +143,13 @@ public:
   // reference to the decoder to prevent further calls into the decoder.
   virtual void NotifyXPCOMShutdown() = 0;
 
+#ifdef MOZ_EME
   // Dispatches a "encrypted" event to the HTMLMediaElement, with the
   // provided init data. Actual dispatch may be delayed until HAVE_METADATA.
   // Main thread only.
   virtual void DispatchEncrypted(const nsTArray<uint8_t>& aInitData,
                                  const nsAString& aInitDataType) = 0;
+#endif
 };
 
 } // namespace mozilla
diff --git a/dom/media/MediaFormatReader.cpp b/dom/media/MediaFormatReader.cpp
index 2093803ad..06e8b963b 100644
--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -346,8 +346,12 @@ MediaFormatReader::DecoderFactory::DoCreateDecoder(TrackType aTrack)
   if (!mOwner->mPlatform) {
     mOwner->mPlatform = new PDMFactory();
     if (mOwner->IsEncrypted()) {
+#ifdef MOZ_EME
       MOZ_ASSERT(mOwner->mCDMProxy);
       mOwner->mPlatform->SetCDMProxy(mOwner->mCDMProxy);
+#else
+      return MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR, "EME not supported");
+#endif
     }
   }
 
@@ -577,6 +581,7 @@ MediaFormatReader::InitInternal()
   return NS_OK;
 }
 
+#ifdef MOZ_EME
 class DispatchKeyNeededEvent : public Runnable {
 public:
   DispatchKeyNeededEvent(AbstractMediaDecoder* aDecoder,
@@ -602,6 +607,7 @@ private:
   nsTArray<uint8_t> mInitData;
   nsString mInitDataType;
 };
+#endif
 
 void
 MediaFormatReader::SetCDMProxy(CDMProxy* aProxy)
@@ -618,7 +624,11 @@ MediaFormatReader::SetCDMProxy(CDMProxy* aProxy)
 bool
 MediaFormatReader::IsWaitingOnCDMResource() {
   MOZ_ASSERT(OnTaskQueue());
+#ifdef MOZ_EME
   return IsEncrypted() && !mCDMProxy;
+#else
+  return false;
+#endif
 }
 
 RefPtr<MediaDecoderReader::MetadataPromise>
@@ -725,11 +735,13 @@ MediaFormatReader::OnDemuxerInitDone(nsresult)
 
   UniquePtr<EncryptionInfo> crypto = mDemuxer->GetCrypto();
   if (mDecoder && crypto && crypto->IsEncrypted()) {
+#ifdef MOZ_EME
     // Try and dispatch 'encrypted'. Won't go if ready state still HAVE_NOTHING.
     for (uint32_t i = 0; i < crypto->mInitDatas.Length(); i++) {
       NS_DispatchToMainThread(
         new DispatchKeyNeededEvent(mDecoder, crypto->mInitDatas[i].mInitData, crypto->mInitDatas[i].mType));
     }
+#endif
     mInfo.mCrypto = *crypto;
   }
 
diff --git a/dom/media/mediasource/TrackBuffersManager.cpp b/dom/media/mediasource/TrackBuffersManager.cpp
index 4265aed81..ac6d82411 100644
--- a/dom/media/mediasource/TrackBuffersManager.cpp
+++ b/dom/media/mediasource/TrackBuffersManager.cpp
@@ -58,6 +58,7 @@ AppendStateToStr(SourceBufferAttributes::AppendState aState)
 
 static Atomic<uint32_t> sStreamSourceID(0u);
 
+#ifdef MOZ_EME
 class DispatchKeyNeededEvent : public Runnable {
 public:
   DispatchKeyNeededEvent(AbstractMediaDecoder* aDecoder,
@@ -83,6 +84,7 @@ private:
   nsTArray<uint8_t> mInitData;
   nsString mInitDataType;
 };
+#endif
 
 TrackBuffersManager::TrackBuffersManager(MediaSourceDecoder* aParentDecoder,
                                          const nsACString& aType)
@@ -1097,12 +1099,14 @@ TrackBuffersManager::OnDemuxerInitDone(nsresult)
 
   UniquePtr<EncryptionInfo> crypto = mInputDemuxer->GetCrypto();
   if (crypto && crypto->IsEncrypted()) {
+#ifdef MOZ_EME
     // Try and dispatch 'encrypted'. Won't go if ready state still HAVE_NOTHING.
     for (uint32_t i = 0; i < crypto->mInitDatas.Length(); i++) {
       NS_DispatchToMainThread(
         new DispatchKeyNeededEvent(mParentDecoder, crypto->mInitDatas[i].mInitData,
                                    crypto->mInitDatas[i].mType));
     }
+#endif
     info.mCrypto = *crypto;
     // We clear our crypto init data array, so the MediaFormatReader will
     // not emit an encrypted event for the same init data again.
diff --git a/dom/media/webaudio/AudioContext.cpp b/dom/media/webaudio/AudioContext.cpp
index f61226a48..a36eda621 100644
--- a/dom/media/webaudio/AudioContext.cpp
+++ b/dom/media/webaudio/AudioContext.cpp
@@ -379,10 +379,12 @@ AudioContext::CreateMediaElementSource(HTMLMediaElement& aMediaElement,
     return nullptr;
   }
 
+#ifdef MOZ_EME
   if (aMediaElement.ContainsRestrictedContent()) {
     aRv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
     return nullptr;
   }
+#endif
 
   if (CheckClosed(aRv)) {
     return nullptr;
diff --git a/dom/webidl/HTMLMediaElement.webidl b/dom/webidl/HTMLMediaElement.webidl
index 456579ec1..313686dac 100644
--- a/dom/webidl/HTMLMediaElement.webidl
+++ b/dom/webidl/HTMLMediaElement.webidl
@@ -153,6 +153,7 @@ partial interface HTMLMediaElement {
   attribute EventHandler onmozinterruptend;
 };
 
+#ifdef MOZ_EME
 // Encrypted Media Extensions
 partial interface HTMLMediaElement {
   [Pref="media.eme.apiVisible"]
@@ -168,6 +169,7 @@ partial interface HTMLMediaElement {
   [Pref="media.eme.apiVisible"]
   attribute EventHandler onwaitingforkey;
 };
+#endif
 
 // This is just for testing
 partial interface HTMLMediaElement {
diff --git a/dom/webidl/Navigator.webidl b/dom/webidl/Navigator.webidl
index 56461e429..5452f3247 100644
--- a/dom/webidl/Navigator.webidl
+++ b/dom/webidl/Navigator.webidl
@@ -348,12 +348,14 @@ partial interface Navigator {
   readonly attribute LegacyMozTCPSocket mozTCPSocket;
 };
 
+#ifdef MOZ_EME
 partial interface Navigator {
   [Pref="media.eme.apiVisible", NewObject]
   Promise<MediaKeySystemAccess>
   requestMediaKeySystemAccess(DOMString keySystem,
                               sequence<MediaKeySystemConfiguration> supportedConfigurations);
 };
+#endif
 
 #ifdef NIGHTLY_BUILD
 partial interface Navigator {
diff --git a/dom/webidl/moz.build b/dom/webidl/moz.build
index f24c366e8..5dc637799 100644
--- a/dom/webidl/moz.build
+++ b/dom/webidl/moz.build
@@ -9,6 +9,7 @@ GENERATED_WEBIDL_FILES = [
 ]
 
 PREPROCESSED_WEBIDL_FILES = [
+    'HTMLMediaElement.webidl',
     'Navigator.webidl',
     'Node.webidl',
     'Promise.webidl',
@@ -210,7 +211,6 @@ WEBIDL_FILES = [
     'HTMLLIElement.webidl',
     'HTMLLinkElement.webidl',
     'HTMLMapElement.webidl',
-    'HTMLMediaElement.webidl',
     'HTMLMenuElement.webidl',
     'HTMLMenuItemElement.webidl',
     'HTMLMetaElement.webidl',