fix: Fixed turning browser.pagethumbnails.capturing_disabled on breaking WS, b=closes #12772, c=no-component

src/zen/drag-and-drop/ZenDragAndDrop.js

@@ -1217,6 +1217,10 @@
       return true;
     }
 
+    _moveTogetherSelectedTabs() {
+      // Override the default behavior of only moving together selected tabs.
+    }
+
     // eslint-disable-next-line complexity
     #applyDragoverIndicator(event, dropElement, movingTabs, draggedTab) {
       // Doesn't show indicator when dragOverSplit

src/zen/sessionstore/ZenWindowSync.sys.mjs

@@ -909,15 +909,19 @@ class nsZenWindowSync {
             }
           );
 
-        let mySrc = await new Promise((r, re) => {
+        let mySrc = await new Promise(r => {
           const reader = new FileReader();
+          if (!browserBlob) {
+            r("");
+            return;
+          }
           reader.readAsDataURL(browserBlob);
           reader.onloadend = function () {
             // result includes identifier 'data:image/png;base64,' plus the base64 data
             r(reader.result);
           };
           reader.onerror = function () {
-            re(new Error("Failed to read blob as data URL"));
+            r("");
           };
         });