[sync] Do not wait for history to load in tests

Most sync integration tests don't need to wait until history loads. It
slows down the tests, and in fact runs into timeouts on some platforms.
Instead, let's rely on tests themselves being robust enough to handle
history initialization, and if that's not the case they should
explicitly wait until history loads.

Change-Id: Iaf06c3055c21eed0b4502559450bdbf5726bb88e
Bug: 1086829,1049597
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2218022
Commit-Queue: Mikel Astiz <mastiz@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#773117}

chrome/browser/sync/test/integration/sync_test.cc

@@ -98,7 +98,6 @@
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/webui/signin/login_ui_service.h"
 #include "chrome/browser/ui/webui/signin/login_ui_service_factory.h"
-#include "chrome/test/base/ui_test_utils.h"
 #endif
 
 using syncer::ProfileSyncService;
@@ -1040,12 +1039,6 @@ void SyncTest::WaitForDataModels(Profile* profile) {
   bookmarks::test::WaitForBookmarkModelToLoad(
       BookmarkModelFactory::GetForBrowserContext(profile));
 
-// TODO(crbug/1049597): Enable wait for history to load for Android.
-#if !defined(OS_ANDROID)
-  ui_test_utils::WaitForHistoryToLoad(HistoryServiceFactory::GetForProfile(
-      profile, ServiceAccessType::EXPLICIT_ACCESS));
-#endif
-
   search_test_utils::WaitForTemplateURLServiceToLoad(
       TemplateURLServiceFactory::GetForProfile(profile));
 #if defined(OS_CHROMEOS)