(Regarding the experimental `React.unstable_Profiler` API and reactjs/rfcs/pull/51.)

PR #13058 changed the behavior of React profiling builds to opt host roots into `ProfileMode` if the React DevTools extension is detected. This was necessary in order to have accurate tree base time measurements for the visual flame graphs.

The Profiler plug-in for DevTools does feature detection to determine if it's enabled by looking at each root and seeing if any of the fibers contain an `actualDuration` attribute,

The problem is that the `actualDuration` attribute will be present on v16.4 fibers, which pre-date PR #13058. As a result, the Profiler UI may enable itself with versions of React that it cannot work correctly with.

Perhaps an easy solution would be to rename one of the `unstable_Profiler`'s fiber attributes prior to the next minor release (e.g. `treeBaseTime` -> `treeBaseDuration`) and change the DevTools Profiler to feature check using this new name instead.
} else {
      root.finishedWork = null;
      
      
      const timeoutHandle = root.timeoutHandle;
      if (enableSuspense && timeoutHandle !== noTimeout) {
        root.timeoutHandle = noTimeout;
        
        cancelTimeout(timeoutHandle);
      }
      const isYieldy = true;
      renderRoot(root, isYieldy, isExpired);
      finishedWork = root.finishedWork;
      if (finishedWork !== null) {
        
        
        if (!shouldYield()) {
          
          completeRoot(root, finishedWork, expirationTime);
        } else {
          
          
          root.finishedWork = finishedWork;
          if (enableProfilerTimer) {
            
            
            pauseActualRenderTimerIfRunning();
          }
        }
      }