Export ProfilerContext in react-relay (#4049)

Summary:
This context allows re-association of log events with their location in the react tree. We're aiming to use this information for understanding performance the same way Meta does.

The matching type was already being exported.

Fixes #4048 (the flow side of the picture)

Pull Request resolved: #4049

Reviewed By: voideanvalue

Differential Revision: D38936883

Pulled By: josephsavona

fbshipit-source-id: ef93e2e58dcb0a4ec14d7f0bd45d9fb11d3367ea

packages/react-relay/hooks.js

@@ -27,6 +27,7 @@ const useRelayEnvironment = require('./relay-hooks/useRelayEnvironment');
 const useSubscribeToInvalidationState = require('./relay-hooks/useSubscribeToInvalidationState');
 const useSubscription = require('./relay-hooks/useSubscription');
 const RelayRuntime = require('relay-runtime');
+const ProfilerContext = require('./relay-hooks/ProfilerContext');
 
 export type * from './relay-hooks/EntryPointTypes.flow';
 export type {
@@ -78,6 +79,8 @@ module.exports = {
   EntryPointContainer: EntryPointContainer,
   RelayEnvironmentProvider: RelayEnvironmentProvider,
 
+  ProfilerContext: ProfilerContext,
+
   fetchQuery: RelayRuntime.fetchQuery,
 
   loadQuery: loadQuery,

packages/react-relay/index.js

@@ -34,6 +34,7 @@ const useRelayEnvironment = require('./relay-hooks/useRelayEnvironment');
 const useSubscribeToInvalidationState = require('./relay-hooks/useSubscribeToInvalidationState');
 const useSubscription = require('./relay-hooks/useSubscription');
 const RelayRuntime = require('relay-runtime');
+const ProfilerContext = require('./relay-hooks/ProfilerContext');
 
 export type {
   $FragmentRef,
@@ -108,6 +109,8 @@ module.exports = {
   EntryPointContainer: EntryPointContainer,
   RelayEnvironmentProvider: RelayEnvironmentProvider,
 
+  ProfilerContext: ProfilerContext,
+
   fetchQuery: RelayRuntime.fetchQuery,
 
   loadQuery: loadQuery,