--- a/browser/modules/ContentLinkHandler.jsm
+++ b/browser/modules/ContentLinkHandler.jsm
@@ -149,47 +149,49 @@ class FaviconLoad {
 
     // Attempt to get an expiration time from the cache.  If this fails, we'll
     // use this default.
     let expiration = Date.now() + MAX_FAVICON_EXPIRATION;
 
     // This stuff isn't available after onStopRequest returns (so don't start
     // any async operations before this!).
     if (this.channel instanceof Ci.nsICacheInfoChannel) {
-      expiration = Math.min(this.channel.cacheTokenExpirationTime * 1000, expiration);
+      try {
+        expiration = Math.min(this.channel.cacheTokenExpirationTime * 1000, expiration);
+      } catch (e) {
+        // Ignore failures to get the expiration time.
+      }
     }
 
-    let type = this.channel.contentType;
-    let blob = new Blob(this.buffers, { type });
+    try {
+      let type = this.channel.contentType;
+      let blob = new Blob(this.buffers, { type });
 
-    if (type != "image/svg+xml") {
-      let octets = await promiseBlobAsOctets(blob);
-      let sniffer = Cc["@mozilla.org/image/loader;1"].
-                    createInstance(Ci.nsIContentSniffer);
-      try {
+      if (type != "image/svg+xml") {
+        let octets = await promiseBlobAsOctets(blob);
+        let sniffer = Cc["@mozilla.org/image/loader;1"].
+                      createInstance(Ci.nsIContentSniffer);
         type = sniffer.getMIMETypeFromContent(this.channel, octets, octets.length);
-      } catch (e) {
-        this._deferred.reject(e);
-        return;
+
+        if (!type) {
+          throw Components.Exception(`Favicon at "${this.icon.iconUri.spec}" did not match a known mimetype.`, Cr.NS_ERROR_FAILURE);
+        }
+
+        blob = blob.slice(0, blob.size, type);
       }
 
-      if (!type) {
-        this._deferred.reject(Components.Exception(`Favicon at "${this.icon.iconUri.spec}" did not match a known mimetype.`, Cr.NS_ERROR_FAILURE));
-        return;
-      }
+      let dataURL = await promiseBlobAsDataURL(blob);
 
-      blob = blob.slice(0, blob.size, type);
+      this._deferred.resolve({
+        expiration,
+        dataURL,
+      });
+    } catch (e) {
+      this._deferred.reject(e);
     }
-
-    let dataURL = await promiseBlobAsDataURL(blob);
-
-    this._deferred.resolve({
-      expiration,
-      dataURL,
-    });
   }
 
   getInterface(iid) {
     if (iid.equals(Ci.nsIChannelEventSink)) {
       return this;
     }
     throw Cr.NS_ERROR_NO_INTERFACE;
   }