diff --git a/externs/mediakeys.js b/externs/mediakeys.js
index 4f90494fad..ecdb3ae467 100644
--- a/externs/mediakeys.js
+++ b/externs/mediakeys.js
@@ -23,6 +23,20 @@
  */
 
 
+/**
+ * @typedef {string}
+ * 'optional', 'required', 'not-allowed'
+ */
+var MediaKeysRequirement;
+
+
+/**
+ * @typedef {string}
+ * 'temporary', 'persistent-license', 'persistent-usage-record'
+ */
+var MediaKeySessionType;
+
+
 /**
  * @typedef {{contentType: string, robustness: string}}
  * gjslint: disable=900
@@ -35,9 +49,9 @@ var MediaKeySystemMediaCapability;
  *   initDataTypes: (Array.<string>|undefined),
  *   audioCapabilities: (Array.<!MediaKeySystemMediaCapability>|undefined),
  *   videoCapabilities: (Array.<!MediaKeySystemMediaCapability>|undefined),
- *   distinctiveIdentifier: (string|undefined),
- *   persistentState: (string|undefined),
- *   sessionTypes: (Array.<string>|undefined)
+ *   distinctiveIdentifier: (MediaKeysRequirement|undefined),
+ *   persistentState: (MediaKeysRequirement|undefined),
+ *   sessionTypes: (Array.<MediaKeySessionType>|undefined)
  * }}
  * gjslint: disable=900
  */
@@ -87,7 +101,7 @@ function MediaKeys() {}
 
 
 /**
- * @param {string=} opt_sessionType defaults to "temporary"
+ * @param {MediaKeySessionType=} opt_sessionType defaults to "temporary"
  * @return {!MediaKeySession}
  * @throws {TypeError} if opt_sessionType is invalid.
  */
diff --git a/externs/shaka/manifest.js b/externs/shaka/manifest.js
index f2d27b805c..9b338e821c 100644
--- a/externs/shaka/manifest.js
+++ b/externs/shaka/manifest.js
@@ -102,11 +102,80 @@ shakaExtern.Manifest;
 shakaExtern.Period;
 
 
+/**
+ * @typedef {{
+ *   initData: !Uint8Array,
+ *   initDataType: string
+ * }}
+ *
+ * @description
+ * Explicit initialization data, which override any initialization data in the
+ * content. The initDataType values and the formats that they correspond to
+ * are specified {@link http://goo.gl/hKBdff here}.
+ *
+ * @property {!Uint8Array} initData
+ *   Initialization data in the format indicated by initDataType.
+ * @property {string} initDataType
+ *   A string to indicate what format initData is in.
+ *
+ * @exportDoc
+ */
+shakaExtern.InitDataOverride;
+
+
+/**
+ * @typedef {{
+ *   keySystem: string,
+ *   licenseServerUri: string,
+ *   distinctiveIdentifierRequired: boolean,
+ *   persistentStateRequired: boolean,
+ *   robustness: string,
+ *   serverCertificate: Uint8Array,
+ *   initData: Array.<!shakaExtern.InitDataOverride>
+ * }}
+ *
+ * @description
+ * DRM configuration for a single key system.
+ *
+ * @property {string} keySystem
+ *   <i>Required.</i> <br>
+ *   The key system, e.g., "com.widevine.alpha".
+ * @property {string} licenseServerUri
+ *   <i>Required.</i> <br>
+ *   The license server URI.
+ * @property {boolean} distinctiveIdentifierRequired
+ *   <i>Defaults to false.</i> <br>
+ *   True if the application requires the key system to support distinctive
+ *   identifiers.
+ * @property {boolean} persistentStateRequired
+ *   <i>Defaults to false.</i> <br>
+ *   True if the application requires the key system to support persistent
+ *   state, e.g., for persistent license storage.
+ * @property {string} robustness
+ *   A key-system-specific string that specifies a required security level.
+ *   <i>Defaults to '', e.g., no specific robustness required.</i> <br>
+ * @property {Uint8Array} serverCertificate
+ *   <i>Defaults to null, e.g., certificate will be requested from the license
+ *   server if required.</i> <br>
+ *   A key-system-specific server certificate used to encrypt license requests.
+ *   Its use is optional and is meant as an optimization to avoid a round-trip
+ *   to request a certificate.
+ * @property {Array.<!shakaExtern.InitDataOverride>} initData
+ *   <i>Defaults to [], e.g., no override.</i> <br>
+ *   A list of initialization data which override any initialization data found
+ *   in the content.  See also shakaExtern.InitDataOverride.
+ *
+ * @exportDoc
+ */
+shakaExtern.DrmInfo;
+
+
 /**
  * @typedef {{
  *   language: string,
  *   type: string,
  *   primary: boolean,
+ *   drmInfos: Array.<!shakaExtern.DrmInfo>,
  *   streams: !Array.<!shakaExtern.Stream>
  * }}
  *
@@ -129,6 +198,10 @@ shakaExtern.Period;
  *   the same type in the same Period. However, the player may use another
  *   StreamSet to meet application preferences, or to achieve better MIME type
  *   or DRM compatibility among other StreamSets.
+ * @property {Array.<!shakaExtern.DrmInfo>} drmInfos
+ *   <i>Defaults to [] (i.e., no DRM).</i> <br>
+ *   An array of DrmInfo objects which describe DRM schemes are compatible with
+ *   the content.
  * @property {!Array.<!shakaExtern.Stream>} streams
  *   <i>Required.</i> <br>
  *   The StreamSets's Streams. There must be at least one Stream.
diff --git a/lib/dash/dash_parser.js b/lib/dash/dash_parser.js
index ae39a8e63d..400b4efcd3 100644
--- a/lib/dash/dash_parser.js
+++ b/lib/dash/dash_parser.js
@@ -813,6 +813,7 @@ shaka.dash.DashParser.prototype.createStreamSets_ = function(adaptationSets) {
           language: lang,
           type: type,
           primary: sets.some(function(s) { return s.main; }),
+          drmInfos: [],  // TODO
           streams:
               sets.map(function(s) { return s.streams; })
                   .reduce(function(all, part) { return all.concat(part); }, [])
diff --git a/spec/dash_parser_manifest_spec.js b/spec/dash_parser_manifest_spec.js
index 778e6eef24..ba537c350e 100644
--- a/spec/dash_parser_manifest_spec.js
+++ b/spec/dash_parser_manifest_spec.js
@@ -144,6 +144,7 @@ describe('DashParser.Manifest', function() {
                   language: 'en',
                   type: 'video',
                   primary: false,
+                  drmInfos: [],
                   streams: [
                     jasmine.objectContaining({
                       id: 1,
@@ -179,6 +180,7 @@ describe('DashParser.Manifest', function() {
                   language: 'es',
                   type: 'text',
                   primary: false,
+                  drmInfos: [],
                   streams: [
                     jasmine.objectContaining({
                       id: 3,
@@ -199,6 +201,7 @@ describe('DashParser.Manifest', function() {
                   language: '',
                   type: 'audio',
                   primary: true,
+                  drmInfos: [],
                   streams: [
                     jasmine.objectContaining({
                       id: 4,
@@ -241,6 +244,7 @@ describe('DashParser.Manifest', function() {
             language: 'en',
             type: 'video',
             primary: false,
+            drmInfos: [],
             streams: [
               jasmine.objectContaining({bandwidth: 100}),
               jasmine.objectContaining({bandwidth: 200})
@@ -271,6 +275,7 @@ describe('DashParser.Manifest', function() {
             language: 'en',
             type: 'video',
             primary: false,
+            drmInfos: [],
             streams: [
               jasmine.objectContaining({bandwidth: 100})
             ]
@@ -279,6 +284,7 @@ describe('DashParser.Manifest', function() {
             language: 'en',
             type: 'video',
             primary: false,
+            drmInfos: [],
             streams: [
               jasmine.objectContaining({bandwidth: 200})
             ]
@@ -308,6 +314,7 @@ describe('DashParser.Manifest', function() {
             language: 'en',
             type: 'video',
             primary: false,
+            drmInfos: [],
             streams: [
               jasmine.objectContaining({bandwidth: 100})
             ]
@@ -316,6 +323,7 @@ describe('DashParser.Manifest', function() {
             language: 'es',
             type: 'video',
             primary: false,
+            drmInfos: [],
             streams: [
               jasmine.objectContaining({bandwidth: 200})
             ]
@@ -345,6 +353,7 @@ describe('DashParser.Manifest', function() {
             language: 'en',
             type: 'video',
             primary: false,
+            drmInfos: [],
             streams: [
               jasmine.objectContaining({bandwidth: 100})
             ]
@@ -353,6 +362,7 @@ describe('DashParser.Manifest', function() {
             language: 'en',
             type: 'audio',
             primary: false,
+            drmInfos: [],
             streams: [
               jasmine.objectContaining({bandwidth: 200})
             ]