Fix inspecting for non-fabric

Summary:
Changelog: [Internal]

I think this started to break when https://github.com/facebook/react/pull/25441 was synced to RN. Before, `closestInstance` would only be non-null under Fabric, after it could be non-null in both. And we were using `closestInstance` to determine which data to send to `selectNode` in devtools. This diff makes a change to call `selectNode` once for non-fabric and once for fabric, one of them would not send anything to devtools frontend, this would make sure it works for both platforms.

Reviewed By: mondaychen

Differential Revision: D41366466

fbshipit-source-id: fcf30d03e443f6fa067782cd31b7cfd2e0cd841e

Libraries/Inspector/DevtoolsOverlay.js

@@ -125,11 +125,11 @@ export default function DevtoolsOverlay({
       getInspectorDataForViewAtPoint(inspectedView, x, y, viewData => {
         const {touchedViewTag, closestInstance, frame} = viewData;
         if (closestInstance != null || touchedViewTag != null) {
+          // We call `selectNode` for both non-fabric(viewTag) and fabric(instance),
+          // this makes sure it works for both architectures.
+          agent.selectNode(findNodeHandle(touchedViewTag));
           if (closestInstance != null) {
-            // Fabric
             agent.selectNode(closestInstance);
-          } else {
-            agent.selectNode(findNodeHandle(touchedViewTag));
           }
           setInspected({
             frame,

Libraries/Inspector/Inspector.js

@@ -142,12 +142,11 @@ class Inspector extends React.Component<
       // Sync the touched view with React DevTools.
       // Note: This is Paper only. To support Fabric,
       // DevTools needs to be updated to not rely on view tags.
-      if (this.state.devtoolsAgent) {
+      const agent = this.state.devtoolsAgent;
+      if (agent) {
+        agent.selectNode(findNodeHandle(touchedViewTag));
         if (closestInstance != null) {
-          // Fabric
-          this.state.devtoolsAgent.selectNode(closestInstance);
-        } else if (touchedViewTag != null) {
-          this.state.devtoolsAgent.selectNode(findNodeHandle(touchedViewTag));
+          agent.selectNode(closestInstance);
         }
       }