Modify sync unit test to use standard sql::test:: helper.

sql/test/test_helpers.h

Index: sql/test/test_helpers.h
diff --git a/sql/test/test_helpers.h b/sql/test/test_helpers.h
index 71f7c3c57513b9923a937717cdf681e0dca490a1..6ea666197bf5eaf56f7eed884eeeb2479a2c82b4 100644
--- a/sql/test/test_helpers.h
+++ b/sql/test/test_helpers.h
@@ -33,6 +33,10 @@ namespace test {
 // actual file size.  The resulting file will return SQLITE_CORRUPT
 // for most operations unless PRAGMA writable_schema is turned ON.
 //
+// This function operates on the raw database file, outstanding database
+// connections may not see the change because of the database cache.  See
+// CorruptSizeInHeaderWithLock().
+//
 // Returns false if any error occurs accessing the file.
 bool CorruptSizeInHeader(const base::FilePath& db_path) WARN_UNUSED_RESULT;
 
@@ -41,6 +45,12 @@ bool CorruptSizeInHeader(const base::FilePath& db_path) WARN_UNUSED_RESULT;
 // code.
 void CorruptSizeInHeaderMemory(unsigned char* header, int64_t db_size);
 
+// Call CorruptSizeInHeader() while holding a SQLite-compatible lock
+// on the database.  This can be used to corrupt a database which is
+// already open elsewhere.  Blocks until a write lock can be acquired.
+bool CorruptSizeInHeaderWithLock(
+    const base::FilePath& db_path) WARN_UNUSED_RESULT;
+
 // Frequently corruption is a result of failure to atomically update
 // pages in different structures.  For instance, if an index update
 // takes effect but the corresponding table update does not.  This