Account for race conditions with stream intercetor

Summary:
Given that stream interceptor is async the folling race conditino could occur.

Frame at time t=0 comes in, we yeild to the event loop while fetching metadata, fetch takes 5 ticks

Frame at time t=1 comes in, we yeild to the event loop but fetch takes 1 tick

At time t=2 the second frame is augmented  and display

At time t=5 the first fetch returns and we display and older frame

This is a simple check to avoid this.

Reviewed By: aigoncharov

Differential Revision: D45314013

fbshipit-source-id: 054e7e6beb52dfbfd94bc9f8ee3d0a758a669f66

desktop/plugins/public/ui-debugger/index.tsx

@@ -63,6 +63,7 @@ export function plugin(client: PluginClient<Events>) {
   const metadata = createState<Map<MetadataId, Metadata>>(new Map());
   const streamInterceptor = getStreamInterceptor();
 
+  let lastFrameTime = 0;
   const device = client.device.os;
 
   client.onMessage('init', (event) => {
@@ -249,7 +250,10 @@ export function plugin(client: PluginClient<Events>) {
         }
       });
 
-      applyFrameData(processedNodes, frameScan.snapshot);
+      if (frameScan.frameTime > lastFrameTime) {
+        applyFrameData(processedNodes, frameScan.snapshot);
+        lastFrameTime = frameScan.frameTime;
+      }
 
       applyFrameworkEvents(frameScan);
       return true;