Update mojo sdk to rev 8af2ccff2eee4bfca1043015abee30482a030b30

third_party/mojo/src/mojo/public/tools/bindings/generators/cpp_templates/union_declaration.tmpl

Index: third_party/mojo/src/mojo/public/tools/bindings/generators/cpp_templates/union_declaration.tmpl
diff --git a/third_party/mojo/src/mojo/public/tools/bindings/generators/cpp_templates/union_declaration.tmpl b/third_party/mojo/src/mojo/public/tools/bindings/generators/cpp_templates/union_declaration.tmpl
new file mode 100644
index 0000000000000000000000000000000000000000..6e6fe95a74c1dc207af7f5d252494a1936fd7e14
--- /dev/null
+++ b/third_party/mojo/src/mojo/public/tools/bindings/generators/cpp_templates/union_declaration.tmpl
@@ -0,0 +1,50 @@
+{%- set class_name = union.name ~ "_Data" -%}
+{%- set enum_name = union.name ~ "_Tag" -%}
+{%- import "struct_macros.tmpl" as struct_macros %}
+
+class {{class_name}} {
+ public:
+  static {{class_name}}* New(mojo::internal::Buffer* buf);
+
+  static bool Validate(const void* data,
+                       mojo::internal::BoundsChecker* bounds_checker);
+
+  enum class {{enum_name}} : uint32_t {
+{%  for field in union.fields %}
+    {{field.name|upper}},
+{%- endfor %}
+  };
+
+  // A note on layout:
+  // "Each non-static data member is allocated as if it were the sole member of
+  // a struct." - Section 9.5.2 ISO/IEC 14882:2011 (The C++ Spec)
+  union MOJO_ALIGNAS(8) Union_ {
+{%- for field in union.fields %}
+{%-   if field.kind|is_string_kind %}
+    uint64_t f_{{field.name}};
+{%-   elif field.kind.spec == 'b' %}
+    uint8_t f_{{field.name}} : 1;
+{%-   elif field.kind|is_enum_kind %}
+    int32_t f_{{field.name}};
+{%-   else %}
+    {{field.kind|cpp_pod_type}} f_{{field.name}};
+{%-   endif %}
+{%- endfor %}
+    uint64_t unknown;
+  };
+
+  uint32_t reserved;
+  {{enum_name}} tag;
+  Union_ data;
+
+  void EncodePointersAndHandles(std::vector<mojo::Handle>* handles);
+  void DecodePointersAndHandles(std::vector<mojo::Handle>* handles);
+ 
+ private:
+  {{class_name}}();
+  ~{{class_name}}() = delete;
+};
+static_assert(sizeof({{class_name}}) == 16,
+              "Bad sizeof({{class_name}})");
+static_assert(sizeof({{class_name}}::Union_) == 8,
+              "Bad sizeof({{class_name}}::Union_)");