Update from https://crrev.com/306655

base/ios/block_types.h

Index: base/ios/block_types.h
diff --git a/base/ios/block_types.h b/base/ios/block_types.h
new file mode 100644
index 0000000000000000000000000000000000000000..e4dde798aa4f0a0805bee6762321c94abb9c186a
--- /dev/null
+++ b/base/ios/block_types.h
@@ -0,0 +1,14 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef BASE_IOS_BLOCK_TYPES_H_
+#define BASE_IOS_BLOCK_TYPES_H_
+
+// A generic procedural block type that takes no arguments and returns nothing.
+typedef void (^ProceduralBlock)(void);
+
+// A block that takes no arguments and returns a bool.
+typedef bool (^ConditionBlock)(void);
+
+#endif  // BASE_IOS_BLOCK_TYPES_H_