fixed sync frame contents retrieval issue

lib/single-file/frame-tree.js

@@ -58,7 +58,7 @@ this.frameTree = this.frameTree || (() => {
 			options = JSON.parse(JSON.stringify(options));
 			sessions.set(sessionId, { frames: [] });
 			initRequest({ windowId, sessionId, options });
-			return sessions.get(sessionId);
+			return sessions.get(sessionId).frames;
 		},
 		initResponse
 	};
@@ -106,7 +106,10 @@ this.frameTree = this.frameTree || (() => {
 			const remainingFrames = windowData.frames.filter(frameData => !frameData.processed).length;
 			if (!remainingFrames) {
 				sessions.delete(message.sessionId);
-				windowData.resolve(windowData.frames.sort((frame1, frame2) => frame2.windowId.split(".").length - frame1.windowId.split(".").length));
+				windowData.frames = windowData.frames.sort((frame1, frame2) => frame2.windowId.split(".").length - frame1.windowId.split(".").length);
+				if (windowData.resolve) {
+					windowData.resolve(windowData.frames);
+				}
 			}
 		}
 	}