Remove the protective clause that is now unnecessary

Instead, we fixed the callsites to stop emitting events for empty components.

src/isomorphic/ReactPerf.js

@@ -236,17 +236,11 @@ function getWasted(flushHistory = getFlushHistory()) {
 
 function getOperations(flushHistory = getFlushHistory()) {
   var stats = [];
-
   flushHistory.forEach((flush, flushIndex) => {
     var {operations, treeSnapshot} = flush;
-
     operations.forEach(operation => {
       var {instanceID, type, payload} = operation;
-      var {displayName, ownerID} = instanceID !== 0 ?
-        treeSnapshot[instanceID] :
-        // Empty components may appear in some operation logs.
-        {displayName: '#empty', ownerID: null};
-
+      var {displayName, ownerID} = treeSnapshot[instanceID];
       var owner = treeSnapshot[ownerID];
       var key = (owner ? owner.displayName + ' > ' : '') + displayName;