--- a/chrome/content/bindings/browser.js
+++ b/chrome/content/bindings/browser.js
@@ -339,17 +339,17 @@ let DOMEvents =  {
 DOMEvents.init();
 
 let ContentScroll =  {
   init: function() {
     addMessageListener("Content:ScrollTo", this);
     addMessageListener("Content:ScrollBy", this);
     addMessageListener("Content:SetResolution", this);
     addMessageListener("Content:SetCacheViewport", this);
-    addMessageListener("Content:SetCssViewportSize", this);
+    addMessageListener("Content:SetWindowSize", this);
 
     addEventListener("scroll", this, false);
     addEventListener("MozScrolledAreaChanged", this, false);
   },
 
   receiveMessage: function(aMessage) {
     let json = aMessage.json;
     switch (aMessage.name) {
@@ -367,17 +367,17 @@ let ContentScroll =  {
           break;
 
         let cwu = Util.getWindowUtils(content);
         cwu.setResolution(json.scale, json.scale);
         cwu.setDisplayPort(displayport.x, displayport.y, displayport.width, displayport.height);
         break;
       }
 
-      case "Content:SetCssViewportSize": {
+      case "Content:SetWindowSize": {
         let cwu = Util.getWindowUtils(content);
         cwu.setCSSViewport(json.width, json.height);
         break;
       }
     }
   },
 
   handleEvent: function(aEvent) {