Move browsing_data counter sync tests to separate file

components/browsing_data/core/counters/browsing_data_counter.cc

Index: components/browsing_data/core/counters/browsing_data_counter.cc
diff --git a/components/browsing_data/core/counters/browsing_data_counter.cc b/components/browsing_data/core/counters/browsing_data_counter.cc
index fecc32c8740d37d4abdbb5f678774b751febc065..bc26908d6b719f6348b62a15e67cd5649f834d92 100644
--- a/components/browsing_data/core/counters/browsing_data_counter.cc
+++ b/components/browsing_data/core/counters/browsing_data_counter.cc
@@ -167,4 +167,13 @@ BrowsingDataCounter::ResultInt BrowsingDataCounter::FinishedResult::Value()
   return value_;
 }
 
+// BrowsingDataCounter::SyncResult -----------------------------------------
+
+BrowsingDataCounter::SyncResult::SyncResult(const BrowsingDataCounter* source,
+                                            ResultInt value,
+                                            bool sync_enabled)
+    : FinishedResult(source, value), sync_enabled_(sync_enabled) {}
+
+BrowsingDataCounter::SyncResult::~SyncResult() {}
+
 }  // namespace browsing_data