[Sync] Refactoring of sync integration test checkers to remove boilerplate await methods.

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

Index: chrome/browser/sync/test/integration/multi_client_status_change_checker.cc
diff --git a/chrome/browser/sync/test/integration/multi_client_status_change_checker.cc b/chrome/browser/sync/test/integration/multi_client_status_change_checker.cc
index ac75172f1e226d2e02d3dd5333b94600dc83e21f..1b8868a53264a1592b431675f04d4667063ccb04 100644
--- a/chrome/browser/sync/test/integration/multi_client_status_change_checker.cc
+++ b/chrome/browser/sync/test/integration/multi_client_status_change_checker.cc
@@ -10,30 +10,14 @@
 
 MultiClientStatusChangeChecker::MultiClientStatusChangeChecker(
     std::vector<browser_sync::ProfileSyncService*> services)
-    : services_(services) {}
-
-MultiClientStatusChangeChecker::~MultiClientStatusChangeChecker() {}
-
-void MultiClientStatusChangeChecker::Wait() {
-  DVLOG(1) << "Await: " << GetDebugMessage();
-
-  if (IsExitConditionSatisfied()) {
-    DVLOG(1) << "Await -> Exit before waiting: " << GetDebugMessage();
-    return;
+    : services_(services), scoped_observer_(this) {
+  for (browser_sync::ProfileSyncService* service : services) {
+    scoped_observer_.Add(service);
   }
-
-  ScopedObserver<browser_sync::ProfileSyncService,
-                 MultiClientStatusChangeChecker>
-      obs(this);
-  for (std::vector<browser_sync::ProfileSyncService*>::iterator it =
-           services_.begin();
-       it != services_.end(); ++it) {
-    obs.Add(*it);
-  }
-
-  StartBlockingWait();
 }
 
+MultiClientStatusChangeChecker::~MultiClientStatusChangeChecker() {}
+
 void MultiClientStatusChangeChecker::OnStateChanged() {
   CheckExitCondition();
 }