(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.
}
  }
  if (enableSuspense && !isExpired && nextLatestAbsoluteTimeoutMs !== -1) {
    
    const suspendedExpirationTime = expirationTime;
    markSuspendedPriorityLevel(root, suspendedExpirationTime);
    
    
    
    const earliestExpirationTime = findEarliestOutstandingPriorityLevel(
      root,
      expirationTime,
    );
    const earliestExpirationTimeMs = expirationTimeToMs(earliestExpirationTime);
    if (earliestExpirationTimeMs < nextLatestAbsoluteTimeoutMs) {
      nextLatestAbsoluteTimeoutMs = earliestExpirationTimeMs;
    }
    
    
    
    
    const currentTimeMs = expirationTimeToMs(requestCurrentTime());
    let msUntilTimeout = nextLatestAbsoluteTimeoutMs - currentTimeMs;
    msUntilTimeout = msUntilTimeout < 0 ? 0 : msUntilTimeout;
    
    const rootExpirationTime = root.expirationTime;
    onSuspend(
      root,
      rootWorkInProgress,
      suspendedExpirationTime,