Fix declaration order in ProfileSyncServiceBundle

ProfileSyncServiceBundle declares test_url_loader_factory_ after
identity_test_env_. When profile_sync_service_bundle.cc passes
a TestURLLoaderFactory pointer to IdentityTestEnvironment constructor,
it's still in undefined state.

Fix this by moving declaration of test_url_loader_factory_.

Change-Id: Ieb38b395becffc0c26400770057196987376df29
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2306259Reviewed-by: Kush Sinha <sinhak@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Anastasiia N <anastasiian@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791186}

components/sync/driver/profile_sync_service_bundle.h

@@ -63,10 +63,10 @@ class ProfileSyncServiceBundle {
 
  private:
   sync_preferences::TestingPrefServiceSyncable pref_service_;
+  network::TestURLLoaderFactory test_url_loader_factory_;
   signin::IdentityTestEnvironment identity_test_env_;
   testing::NiceMock<SyncApiComponentFactoryMock> component_factory_;
   std::unique_ptr<invalidation::ProfileIdentityProvider> identity_provider_;
-  network::TestURLLoaderFactory test_url_loader_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncServiceBundle);
 };