Move browsing_data counter sync tests to separate file

components/browsing_data/core/counters/passwords_counter.cc

Index: components/browsing_data/core/counters/passwords_counter.cc
diff --git a/components/browsing_data/core/counters/passwords_counter.cc b/components/browsing_data/core/counters/passwords_counter.cc
index 5bc03978b99223bc19f4b292836129cf4cef54f5..b78cd06b8f2119bd593c89369ad85c7ddd7af87f 100644
--- a/components/browsing_data/core/counters/passwords_counter.cc
+++ b/components/browsing_data/core/counters/passwords_counter.cc
@@ -63,8 +63,8 @@ void PasswordsCounter::OnGetPasswordStoreResults(
       [start](const std::unique_ptr<autofill::PasswordForm>& form) {
         return form->date_created >= start;
       });
-  ReportResult(base::MakeUnique<PasswordResult>(this, num_passwords,
-                                                password_sync_enabled_));
+  ReportResult(base::MakeUnique<SyncResult>(this, num_passwords,
+                                            password_sync_enabled_));
 }
 
 void PasswordsCounter::OnLoginsChanged(
@@ -81,14 +81,4 @@ void PasswordsCounter::OnStateChanged(syncer::SyncService* sync) {
   }
 }
 
-// PasswordsCounter::PasswordResult
-
-PasswordsCounter::PasswordResult::PasswordResult(const PasswordsCounter* source,
-                                                 ResultInt value,
-                                                 bool password_sync_enabled)
-    : FinishedResult(source, value),
-      password_sync_enabled_(password_sync_enabled) {}
-
-PasswordsCounter::PasswordResult::~PasswordResult() {}
-
 }  // namespace browsing_data