Bug 1111967 - honor browser.casting.enabled pref for casting on desktop, r=mconley

browser/app/profile/firefox.js

@@ -285,6 +285,7 @@ pref("browser.slowStartup.maxSamples", 5);
 pref("browser.aboutHomeSnippets.updateUrl", "https://snippets.cdn.mozilla.net/%STARTPAGE_VERSION%/%NAME%/%VERSION%/%APPBUILDID%/%BUILD_TARGET%/%LOCALE%/%CHANNEL%/%OS_VERSION%/%DISTRIBUTION%/%DISTRIBUTION_VERSION%/");
 
 pref("browser.enable_automatic_image_resizing", true);
+pref("browser.casting.enabled", true);
 pref("browser.chrome.site_icons", true);
 pref("browser.chrome.favicons", true);
 // browser.warnOnQuit == false will override all other possible prompts when quitting or restarting

browser/base/content/browser.js

@@ -2949,7 +2949,10 @@ function BrowserFullScreen()
 }
 
 function mirrorShow(popup) {
-  let services = CastingApps.getServicesForMirroring();
+  let services = [];
+  if (Services.prefs.getBoolPref("browser.casting.enabled")) {
+    services = CastingApps.getServicesForMirroring();
+  }
   popup.ownerDocument.getElementById("menu_mirrorTabCmd").hidden = !services.length;
 }
 
@@ -2959,8 +2962,11 @@ function mirrorMenuItemClicked(event) {
 }
 
 function populateMirrorTabMenu(popup) {
-  let videoEl = this.target;
   popup.innerHTML = null;
+  if (!Services.prefs.getBoolPref("browser.casting.enabled")) {
+    return;
+  }
+  let videoEl = this.target;
   let doc = popup.ownerDocument;
   let services = CastingApps.getServicesForMirroring();
   services.forEach(service => {

browser/base/content/content.js

@@ -105,6 +105,9 @@ addMessageListener("MixedContent:ReenableProtection", function() {
 });
 
 addMessageListener("SecondScreen:tab-mirror", function(message) {
+  if (!Services.prefs.getBoolPref("browser.casting.enabled")) {
+    return;
+  }
   let app = SimpleServiceDiscovery.findAppForService(message.data.service);
   if (app) {
     let width = content.innerWidth;

browser/base/content/nsContextMenu.js

@@ -218,12 +218,13 @@ nsContextMenu.prototype = {
     this.showItem("context-sendaudio", this.onAudio);
     this.setItemAttr("context-sendvideo", "disabled", !this.mediaURL);
     this.setItemAttr("context-sendaudio", "disabled", !this.mediaURL);
+    let shouldShowCast = Services.prefs.getBoolPref("browser.casting.enabled");
     // getServicesForVideo alone would be sufficient here (it depends on
-    // SimpleServiceDiscovery.services), but SimpleServiceDiscovery is garanteed
+    // SimpleServiceDiscovery.services), but SimpleServiceDiscovery is guaranteed
-    // to be already loaded, since we load it on startup, and CastingApps isn't,
+    // to be already loaded, since we load it on startup in nsBrowserGlue,
-    // so check SimpleServiceDiscovery.services first to avoid needing to load
+    // and CastingApps isn't, so check SimpleServiceDiscovery.services first
-    // CastingApps.jsm if we don't need to.
+    // to avoid needing to load CastingApps.jsm if we don't need to.
-    let shouldShowCast = this.mediaURL &&
+    shouldShowCast = shouldShowCast && this.mediaURL &&
                      SimpleServiceDiscovery.services.length > 0 &&
                      CastingApps.getServicesForVideo(this.target).length > 0;
     this.setItemAttr("context-castvideo", "disabled", !shouldShowCast);

browser/components/nsBrowserGlue.js

@@ -987,6 +987,9 @@ BrowserGlue.prototype = {
   },
 
   _initServiceDiscovery: function () {
+    if (!Services.prefs.getBoolPref("browser.casting.enabled")) {
+      return;
+    }
     var rokuDevice = {
       id: "roku:ecp",
       target: "roku:ecp",