--- a/browser/modules/AsyncTabSwitcher.jsm
+++ b/browser/modules/AsyncTabSwitcher.jsm
@@ -97,21 +97,16 @@ class AsyncTabSwitcher {
     this.unloadTimer = null; // UNLOAD_DELAY nsITimer instance.
 
     // Map from tabs to STATE_* (below).
     this.tabState = new Map();
 
     // True if we're in the midst of switching tabs.
     this.switchInProgress = false;
 
-    // Keep an exact list of content processes (tabParent) in which
-    // we're actively suppressing the display port. This gives a robust
-    // way to make sure we don't forget to un-suppress.
-    this.activeSuppressDisplayport = new Set();
-
     // Set of tabs that might be visible right now. We maintain
     // this set because we can't be sure when a tab is actually
     // drawn. A tab is added to this set when we ask to make it
     // visible. All tabs but the most recently shown tab are
     // removed from the set upon MozAfterPaint.
     this.maybeVisibleTabs = new Set([tabbrowser.selectedTab]);
 
     // This holds onto the set of tabs that we've been asked to warm up,
@@ -183,21 +178,16 @@ class AsyncTabSwitcher {
     this.window.removeEventListener("MozLayerTreeCleared", this);
     this.window.removeEventListener("TabRemotenessChange", this);
     this.window.removeEventListener("sizemodechange", this);
     this.window.removeEventListener("occlusionstatechange", this);
     this.window.removeEventListener("SwapDocShells", this, true);
     this.window.removeEventListener("EndSwapDocShells", this, true);
 
     this.tabbrowser._switcher = null;
-
-    this.activeSuppressDisplayport.forEach(function(tabParent) {
-      tabParent.suppressDisplayport(false);
-    });
-    this.activeSuppressDisplayport.clear();
   }
 
   // Wraps nsITimer. Must not use the vanilla setTimeout and
   // clearTimeout, because they will be blocked by nsIPromptService
   // dialogs.
   setTimer(callback, timeout) {
     let event = {
       notify: callback
@@ -871,17 +861,17 @@ class AsyncTabSwitcher {
     if (!this.shouldWarmTab(tab)) {
       return;
     }
 
     this.logState("warmupTab " + this.tinfo(tab));
 
     this.warmingTabs.add(tab);
     this.setTabState(tab, this.STATE_LOADING);
-    this.suppressDisplayPortAndQueueUnload(tab, gTabWarmingUnloadDelayMs);
+    this.queueUnload(gTabWarmingUnloadDelayMs);
   }
 
   // Called when the user asks to switch to a given tab.
   requestTab(tab) {
     if (tab === this.requestedTab) {
       return;
     }
 
@@ -917,29 +907,21 @@ class AsyncTabSwitcher {
     this.requestedTab = tab;
 
     tab.linkedBrowser.setAttribute("primary", "true");
     if (this.lastPrimaryTab && this.lastPrimaryTab != tab) {
       this.lastPrimaryTab.linkedBrowser.removeAttribute("primary");
     }
     this.lastPrimaryTab = tab;
 
-    this.suppressDisplayPortAndQueueUnload(this.requestedTab, this.UNLOAD_DELAY);
+    this.queueUnload(this.UNLOAD_DELAY);
     this._requestingTab = false;
   }
 
-  suppressDisplayPortAndQueueUnload(tab, unloadTimeout) {
-    let browser = tab.linkedBrowser;
-    let fl = browser.frameLoader;
-
-    if (fl && fl.tabParent && !this.activeSuppressDisplayport.has(fl.tabParent)) {
-      fl.tabParent.suppressDisplayport(true);
-      this.activeSuppressDisplayport.add(fl.tabParent);
-    }
-
+  queueUnload(unloadTimeout) {
     this.preActions();
 
     if (this.unloadTimer) {
       this.clearTimer(this.unloadTimer);
     }
     this.unloadTimer = this.setTimer(() => this.onUnloadTimeout(), unloadTimeout);
 
     this.postActions();