C bindings: Implement _DeepCopy() & some unittests.

mojo/public/c/bindings/lib/type_descriptor.h

Index: mojo/public/c/bindings/lib/type_descriptor.h
diff --git a/mojo/public/c/bindings/lib/type_descriptor.h b/mojo/public/c/bindings/lib/type_descriptor.h
index cf684ddf7d4c3a368bf8d2f486447ded67611dd5..a4cca9bb1df159ae6a99a5144045261e6c8af939 100644
--- a/mojo/public/c/bindings/lib/type_descriptor.h
+++ b/mojo/public/c/bindings/lib/type_descriptor.h
@@ -163,11 +163,11 @@ size_t MojomType_DispatchComputeSerializedSize(
     bool nullable,
     const void* data);
 
-// This helper function, depending on |type|, calls the appropriate
-// *_DispatchEncodePointersAndHandles(...). If |type| describes a pointer, it
+// This helper function, depending on |in_elem_type|, calls the appropriate
+// *_EncodePointersAndHandles(...). If |in_elem_type| describes a pointer, it
 // first encodes the pointer before calling the associated
-// *_DispatchEncodePointersAndHandles(...). If |type| describes a handle, it
-// encodes handle into |inout_handles|.
+// *_EncodePointersAndHandles(...). If |in_elem_type| describes a handle, it
+// encodes the handle into |inout_handles|.
 void MojomType_DispatchEncodePointersAndHandles(
     enum MojomTypeDescriptorType in_elem_type,
     const void* in_type_desc,
@@ -176,10 +176,10 @@ void MojomType_DispatchEncodePointersAndHandles(
     uint32_t in_buf_size,
     struct MojomHandleBuffer* inout_handles_buffer);
 
-// This helper function, depending on |type|, calls the appropriate
-// *_DispatchDeocdePointersAndHandles(...). If |type| describes a pointer, it
+// This helper function, depending on |in_elem_type|, calls the appropriate
+// *_DecodePointersAndHandles(...). If |in_elem_type| describes a pointer, it
 // first decodes the offset into a pointer before calling the associated
-// *_DispatchDecodePointersAndHandles(...). If |type| describes a handle, it
+// *_DecodePointersAndHandles(...). If |in_elem_type| describes a handle, it
 // decodes the handle by looking up it up in |inout_handles|.
 void MojomType_DispatchDecodePointersAndHandles(
     enum MojomTypeDescriptorType in_elem_type,
@@ -199,6 +199,18 @@ MojomValidationResult MojomType_DispatchValidate(
     uint32_t in_num_handles,
     struct MojomValidationContext* inout_context);
 
+// This helper function, depending on |in_elem_type|, calls the appropriate
+// *_DeepCopy(...). The result of that call is then assigned to |out_data|. If
+// |in_elem_type| describes a handle, this function moves the handle from
+// |in_data| into |out_data| and invalidates |in_data|. If |in_type_type|
+// describes a pointer to a union, it allocates space for the new union before
+// dispatching a call to MojomUnion_DeepCopy.
+void MojomType_DispatchDeepCopy(struct MojomBuffer* buffer,
+                                enum MojomTypeDescriptorType in_elem_type,
+                                const void* in_type_desc,
+                                void* in_data,
+                                void* out_data);
+
 MOJO_END_EXTERN_C
 
 #endif  // MOJO_PUBLIC_C_BINDINGS_LIB_TYPE_DESCRIPTOR_H_