[ObjC ARC] Converts ios/chrome/test/app:test_support to ARC.

ios/chrome/browser/ui/sync/sync_fake_server_egtest.mm

Index: ios/chrome/browser/ui/sync/sync_fake_server_egtest.mm
diff --git a/ios/chrome/browser/ui/sync/sync_fake_server_egtest.mm b/ios/chrome/browser/ui/sync/sync_fake_server_egtest.mm
index 71cd0e379dec6417455ce2e4d0f04374255e2d8e..2ec6b8b7acdedbdc58fe3ff5c59362215f9766a0 100644
--- a/ios/chrome/browser/ui/sync/sync_fake_server_egtest.mm
+++ b/ios/chrome/browser/ui/sync/sync_fake_server_egtest.mm
@@ -38,6 +38,10 @@
 #include "ui/base/l10n/l10n_util.h"
 #include "url/gurl.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 // Constant for timeout while waiting for asynchronous sync operations.
@@ -455,9 +459,6 @@ void AssertNumberOfEntitiesWithName(int entity_count,
                   }];
   BOOL success = [condition waitWithTimeout:kSyncOperationTimeout];
   DCHECK(success || blockSafeError);
-  if (blockSafeError) {
-    [blockSafeError autorelease];
-  }
   GREYAssertTrue(success, [blockSafeError localizedDescription]);
 }
 
@@ -580,9 +581,6 @@ void AssertNumberOfEntitiesWithName(int entity_count,
                   }];
   BOOL success = [condition waitWithTimeout:kSyncOperationTimeout];
   DCHECK(success || blockSafeError);
-  if (blockSafeError) {
-    [blockSafeError autorelease];
-  }
   GREYAssert(success, [blockSafeError localizedDescription]);
 }