[sql] Serialize calls to sqlite3_initialize().

sql/connection.cc

Index: sql/connection.cc
diff --git a/sql/connection.cc b/sql/connection.cc
index f04eb3bd7ee3c135892fd9225043e59fdcaf6eed..a81cc5019aec323e7dc51e3a860ac1d2cbc66347 100644
--- a/sql/connection.cc
+++ b/sql/connection.cc
@@ -8,6 +8,7 @@
 
 #include "base/files/file_path.h"
 #include "base/file_util.h"
+#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
@@ -15,6 +16,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/synchronization/lock.h"
 #include "sql/statement.h"
 #include "third_party/sqlite/sqlite3.h"
 
@@ -94,6 +96,20 @@ int BackupDatabase(sqlite3* src, sqlite3* dst, const char* db_name) {
   return rc;
 }
 
+// SQLite automatically calls sqlite3_initialize() lazily, but
+// sqlite3_initialize() uses double-checked locking and thus can have
+// data races.
+//
+// TODO(shess): Another alternative would be to have
+// sqlite3_initialize() called as part of process bring-up.  If this
+// is changed, remove the dynamic_annotations dependency in sql.gyp.
+base::LazyInstance<base::Lock>::Leaky
+    g_sqlite_init_lock = LAZY_INSTANCE_INITIALIZER;
+void InitializeSqlite() {
+  base::AutoLock lock(g_sqlite_init_lock.Get());
+  sqlite3_initialize();
+}
+
 }  // namespace
 
 namespace sql {
@@ -707,6 +723,9 @@ bool Connection::OpenInternal(const std::string& file_name) {
     return false;
   }
 
+  // Make sure sqlite3_initialize() is called before anything else.
+  InitializeSqlite();
+
   // If |poisoned_| is set, it means an error handler called
   // RazeAndClose().  Until regular Close() is called, the caller
   // should be treating the database as open, but is_open() currently