`getContextChangedKeys` only handles class components:
https://github.com/facebook/react/blob/355591add41c0f6dad738fdb1b6603e0786b7b4e/packages/react-devtools-shared/src/backend/renderer.js#L1276-L1304
Capture initial values as of the time profiling starts.
     It's important we snapshot both the durations and the id-to-root map,
     since either of these may change during the profiling session
     (e.g. when a fiber is re-rendered or when a fiber gets removed).
    displayNamesByRootID = new Map();
    initialTreeBaseDurationsMap = new Map(idToTreeBaseDurationMap);
    initialIDToRootMap = new Map(idToRootMap);
    idToContextsMap = new Map();
    hook.getFiberRoots(rendererID).forEach(root => {
      const rootID = getFiberIDThrows(root.current);
      ((displayNamesByRootID: any): DisplayNamesByRootID).set(
        rootID,
        getDisplayNameForRoot(root.current),
      );
      if (shouldRecordChangeDescriptions) {
         R
         F
         s
        crawlToInitializeContextsMap(root.current);
      }
    });
    isProfiling = true;
    profilingStartTime = getCurrentTime();
    rootToCommitProfilingMetadataMap = new Map();
  }
  function stopProfiling() {
    isProfiling = false;
    recordChangeDescriptions = false;
  }
   Automatically start profiling so that we don't miss timing info from initial "mount".