perf: Prevent CastSender initialization on CastProxy on unsupported browsers (#7995)

Author: avelad

lib/cast/cast_proxy.js

@@ -81,17 +81,21 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
     this.compiledToExternNames_ = new Map();
 
     /** @private {shaka.cast.CastSender} */
-    this.sender_ = new shaka.cast.CastSender(
-        receiverAppId,
-        () => this.onCastStatusChanged_(),
-        () => this.onFirstCastStateUpdate_(),
-        (targetName, event) => this.onRemoteEvent_(targetName, event),
-        () => this.onResumeLocal_(),
-        () => this.getInitState_(),
-        androidReceiverCompatible);
-
+    this.sender_ = null;
 
-    this.init_();
+    if (window.chrome) {
+      this.sender_ = new shaka.cast.CastSender(
+          receiverAppId,
+          () => this.onCastStatusChanged_(),
+          () => this.onFirstCastStateUpdate_(),
+          (targetName, event) => this.onRemoteEvent_(targetName, event),
+          () => this.onResumeLocal_(),
+          () => this.getInitState_(),
+          androidReceiverCompatible);
+      this.init_();
+    } else {
+      this.initWithoutSender_();
+    }
   }
 
   /**
@@ -163,6 +167,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
    * @export
    */
   canCast() {
+    if (!this.sender_) {
+      return false;
+    }
     return this.sender_.apiReady() && this.sender_.hasReceivers();
   }
 
@@ -171,6 +178,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
    * @export
    */
   isCasting() {
+    if (!this.sender_) {
+      return false;
+    }
     return this.sender_.isCasting();
   }
 
@@ -179,6 +189,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
    * @export
    */
   receiverName() {
+    if (!this.sender_) {
+      return '';
+    }
     return this.sender_.receiverName();
   }
 
@@ -188,6 +201,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
    * @export
    */
   async cast() {
+    if (!this.sender_) {
+      return;
+    }
     // TODO: transfer manually-selected tracks?
     // TODO: transfer side-loaded text tracks?
 
@@ -208,6 +224,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
    * @export
    */
   setAppData(appData) {
+    if (!this.sender_) {
+      return;
+    }
     this.sender_.setAppData(appData);
   }
 
@@ -216,6 +235,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
    * @export
    */
   suggestDisconnect() {
+    if (!this.sender_) {
+      return;
+    }
     this.sender_.showDisconnectDialog();
   }
 
@@ -224,6 +246,9 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
    * @export
    */
   forceDisconnect() {
+    if (!this.sender_) {
+      return;
+    }
     this.sender_.forceDisconnect();
   }
 
@@ -243,6 +268,10 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
     this.receiverAppId_ = newAppId;
     this.androidReceiverCompatible_ = newCastAndroidReceiver;
 
+    if (!this.sender_) {
+      return;
+    }
+
     // Destroy the old sender
     this.sender_.forceDisconnect();
     await this.sender_.destroy();
@@ -262,6 +291,15 @@ shaka.cast.CastProxy = class extends shaka.util.FakeEventTarget {
     this.sender_.init();
   }
 
+  /**
+   * Initialize the Proxies without Cast sender.
+   * @private
+   */
+  initWithoutSender_() {
+    this.videoProxy_ = /** @type {Object} */(this.localVideo_);
+    this.playerProxy_ = /** @type {Object} */(this.localPlayer_);
+  }
+
   /**
    * Initialize the Proxies and the Cast sender.
    * @private

test/cast/cast_proxy_unit.js

@@ -23,7 +23,11 @@ describe('CastProxy', () => {
   /** @type {shaka.cast.CastProxy} */
   let proxy;
 
+  const originalWindowChrome = window.chrome;
+
   beforeEach(() => {
+    window['chrome'] = originalWindowChrome || {};
+
     mockCastSenderConstructor = jasmine.createSpy('CastSender constructor');
     mockCastSenderConstructor.and.callFake(createMockCastSender);
     shaka.cast.CastSender = Util.spyFunc(mockCastSenderConstructor);
@@ -42,6 +46,7 @@ describe('CastProxy', () => {
     } finally {
       shaka.cast.CastSender = originalCastSender;
     }
+    window['chrome'] = originalWindowChrome;
   });
 
   describe('constructor', () => {