Don't use dot notation for bogus properties

DrmEngine is adding an extra property to MediaKeySystemConfiguration
objects, knowing that EME will ignore it.  The latest Closure Compiler
won't allow this.

In the future, we should refactor DrmEngine and consider tracking this
in some other way.  For now, this changes the dot to square brackets.

Issue shaka-project#2528

Change-Id: I544c93dfa2534e9d62ac5ea47e20a6dc3cb79e3a

lib/media/drm_engine.js

@@ -242,26 +242,31 @@ shaka.media.DrmEngine = class {
       audioCapabilities, videoCapabilities) {
     /** @type {!Map.<string, MediaKeySystemConfiguration>} */
     const configsByKeySystem = new Map();
-    configsByKeySystem.set(keySystem, {
+
+    /** @type {MediaKeySystemConfiguration} */
+    const config = {
       audioCapabilities: audioCapabilities,
       videoCapabilities: videoCapabilities,
       distinctiveIdentifier: 'optional',
       persistentState: 'required',
       sessionTypes: ['persistent-license'],
       label: keySystem,  // Tracked by us, ignored by EME.
-      drmInfos: [{
-        keySystem: keySystem,
-        licenseServerUri: licenseServerUri,
-        distinctiveIdentifierRequired: false,
-        persistentStateRequired: true,
-        audioRobustness: '',  // Not required by queryMediaKeys_
-        videoRobustness: '',  // Same
-        serverCertificate: serverCertificate,
-        initData: null,
-        keyIds: null,
-      }],
-    });
+    };
+
+    // TODO: refactor, don't stick drmInfos onto MediaKeySystemConfiguration
+    config['drmInfos'] = [{  // Non-standard attribute, ignored by EME.
+      keySystem: keySystem,
+      licenseServerUri: licenseServerUri,
+      distinctiveIdentifierRequired: false,
+      persistentStateRequired: true,
+      audioRobustness: '',  // Not required by queryMediaKeys_
+      videoRobustness: '',  // Same
+      serverCertificate: serverCertificate,
+      initData: null,
+      keyIds: null,
+    }];
 
+    configsByKeySystem.set(keySystem, config);
     return this.queryMediaKeys_(configsByKeySystem);
   }
 
@@ -682,8 +687,9 @@ shaka.media.DrmEngine = class {
         persistentState: persistentState,
         sessionTypes: sessionTypes,
         label: info.keySystem,  // Tracked by us, ignored by EME.
-        drmInfos: [],
       };
+      // TODO: refactor, don't stick drmInfos onto MediaKeySystemConfiguration
+      config['drmInfos'] = [];  // Non-standard attribute, ignored by EME.
 
       // Multiple calls to |set| will still respect the insertion order of the
       // first call to |set| for a given key.
@@ -712,7 +718,9 @@ shaka.media.DrmEngine = class {
               config,
               'Any missing configs should have be filled in before.');
 
-          config.drmInfos.push(info);
+          // TODO: refactor, don't stick drmInfos onto
+          // MediaKeySystemConfiguration
+          config['drmInfos'].push(info);
 
           if (info.distinctiveIdentifierRequired) {
             config.distinctiveIdentifier = 'required';
@@ -778,7 +786,8 @@ shaka.media.DrmEngine = class {
     for (const shouldHaveLicenseServer of [true, false]) {
       for (const keySystem of configsByKeySystem.keys()) {
         const config = configsByKeySystem.get(keySystem);
-        const hasLicenseServer = config.drmInfos.some((info) => {
+        // TODO: refactor, don't stick drmInfos onto MediaKeySystemConfiguration
+        const hasLicenseServer = config['drmInfos'].some((info) => {
           return !!info.licenseServerUri;
         });
         if (hasLicenseServer != shouldHaveLicenseServer) {
@@ -1749,8 +1758,9 @@ shaka.media.DrmEngine = class {
     /** @type {!Set.<string>} */
     const keyIds = new Set();
 
+    // TODO: refactor, don't stick drmInfos onto MediaKeySystemConfiguration
     shaka.media.DrmEngine.processDrmInfos_(
-        config.drmInfos, licenseServers, serverCerts, initDatas, keyIds);
+        config['drmInfos'], licenseServers, serverCerts, initDatas, keyIds);
 
     if (serverCerts.length > 1) {
       shaka.log.warning('Multiple unique server certificates found! ' +