[Sync] Refactored ProfileSyncService and remove its backend() function

chrome/browser/sync/profile_sync_service_harness.cc

Index: chrome/browser/sync/profile_sync_service_harness.cc
diff --git a/chrome/browser/sync/profile_sync_service_harness.cc b/chrome/browser/sync/profile_sync_service_harness.cc
index 6f2cb909010c6c5442805c637d0c1409947360ee..4243c4cb7928e3be60ca65e5bbf0264f0da1e689 100644
--- a/chrome/browser/sync/profile_sync_service_harness.cc
+++ b/chrome/browser/sync/profile_sync_service_harness.cc
@@ -447,7 +447,7 @@ bool ProfileSyncServiceHarness::IsSynced() {
           snap->num_conflicting_updates == 0 &&  // We can decrypt everything.
           ServiceIsPushingChanges() &&
           GetStatus().notifications_enabled &&
-          !service()->backend()->HasUnsyncedItems() &&
+          !service()->HasUnsyncedItems() &&
           !snap->has_more_to_sync &&
           snap->unsynced_count == 0);
 }
@@ -480,8 +480,8 @@ bool ProfileSyncServiceHarness::MatchesOtherClient(
 const SyncSessionSnapshot*
     ProfileSyncServiceHarness::GetLastSessionSnapshot() const {
   DCHECK(service_ != NULL) << "Sync service has not yet been set up.";
-  if (service_->backend()) {
-    return service_->backend()->GetLastSessionSnapshot();
+  if (service_->sync_initialized()) {
+    return service_->GetLastSessionSnapshot();
   }
   return NULL;
 }
@@ -582,7 +582,7 @@ void ProfileSyncServiceHarness::LogClientInfo(std::string message) {
               << ", unsynced_count: " << snap->unsynced_count
               << ", num_conflicting_updates: " << snap->num_conflicting_updates
               << ", has_unsynced_items: "
-              << service()->backend()->HasUnsyncedItems()
+              << service()->HasUnsyncedItems()
               << ", observed_passphrase_required: "
               << service()->observed_passphrase_required()
               << ", notifications_enabled: "