[sql] Serialize calls to sqlite3_initialize().

sql/connection.cc

Index: sql/connection.cc
diff --git a/sql/connection.cc b/sql/connection.cc
index 4550b0e5569304a75e77ef8a58298304fa7b2c1d..c10f5a77ce8c484d16462cc74635882ee25bc17a 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"
 
@@ -109,6 +111,20 @@ bool ValidAttachmentPoint(const char* attachment_point) {
   return true;
 }
 
+// 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 {
@@ -799,6 +815,9 @@ 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