Remove support for interfaces.

runtime/lib/mirrors.cc

Index: runtime/lib/mirrors.cc
===================================================================
--- runtime/lib/mirrors.cc	(revision 15556)
+++ runtime/lib/mirrors.cc	(working copy)
@@ -259,7 +259,7 @@
     return Dart_New(cls, Dart_Null(), ARRAY_SIZE(args), args);
   }
 
-  if (Dart_IsClass(target) || Dart_IsInterface(target)) {
+  if (Dart_IsClass(target)) {
     if (Dart_ClassIsFunctionType(target)) {
       Dart_Handle cls_name = NewString("_LazyFunctionTypeMirror");
       Dart_Handle cls = Dart_GetClass(MirrorLib(), cls_name);
@@ -364,7 +364,7 @@
 
 static Dart_Handle CreateTypeVariableMap(Dart_Handle owner,
                                          Dart_Handle owner_mirror) {
-  ASSERT(Dart_IsClass(owner) || Dart_IsInterface(owner));
+  ASSERT(Dart_IsClass(owner));
   // TODO(turnidge): This should be an immutable map.
   Dart_Handle map = MapNew();
   if (Dart_IsError(map)) {
@@ -436,7 +436,7 @@
                                      Dart_Handle intf_name,
                                      Dart_Handle lib,
                                      Dart_Handle lib_mirror) {
-  ASSERT(Dart_IsClass(intf) || Dart_IsInterface(intf));
+  ASSERT(Dart_IsClass(intf));
   if (Dart_ClassIsTypedef(intf)) {
     // This class is actually a typedef.  Represent it specially in
     // reflection.