- Add a minimal implementation of Capability.

runtime/vm/object_store.h

Index: runtime/vm/object_store.h
===================================================================
--- runtime/vm/object_store.h	(revision 35191)
+++ runtime/vm/object_store.h	(working copy)
@@ -241,6 +241,21 @@
     return OFFSET_OF(ObjectStore, error_class_);
   }
 
+  RawClass* capability_class() const { return capability_class_; }
+  void set_capability_class(const Class& value) {
+    capability_class_ = value.raw();
+  }
+
+  RawClass* receive_port_class() const { return receive_port_class_; }
+  void set_receive_port_class(const Class& value) {
+    receive_port_class_ = value.raw();
+  }
+
+  RawClass* send_port_class() const { return send_port_class_; }
+  void set_send_port_class(const Class& value) {
+    send_port_class_ = value.raw();
+  }
+
   RawClass* stacktrace_class() const {
     return stacktrace_class_;
   }
@@ -407,20 +422,13 @@
     preallocated_stack_trace_ = value.raw();
   }
 
-  RawFunction* receive_port_create_function() const {
-    return receive_port_create_function_;
+  RawFunction* lookup_port_handler() const {
+    return lookup_port_handler_;
   }
-  void set_receive_port_create_function(const Function& function) {
-    receive_port_create_function_ = function.raw();
+  void set_lookup_port_handler(const Function& function) {
+    lookup_port_handler_ = function.raw();
   }
 
-  RawFunction* lookup_receive_port_function() const {
-    return lookup_receive_port_function_;
-  }
-  void set_lookup_receive_port_function(const Function& function) {
-    lookup_receive_port_function_ = function.raw();
-  }
-
   RawFunction* handle_message_function() const {
     return handle_message_function_;
   }
@@ -483,6 +491,9 @@
   RawClass* float64x2_class_;
   RawArray* typed_data_classes_;
   RawClass* error_class_;
+  RawClass* capability_class_;
+  RawClass* receive_port_class_;
+  RawClass* send_port_class_;
   RawClass* stacktrace_class_;
   RawClass* jsregexp_class_;
   RawClass* weak_property_class_;
@@ -512,8 +523,7 @@
   RawInstance* stack_overflow_;
   RawInstance* out_of_memory_;
   RawStacktrace* preallocated_stack_trace_;
-  RawFunction* receive_port_create_function_;
-  RawFunction* lookup_receive_port_function_;
+  RawFunction* lookup_port_handler_;
   RawFunction* handle_message_function_;
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&handle_message_function_);