Remove element from DynamicType.

sdk/lib/_internal/compiler/implementation/helpers/trace.dart

Index: sdk/lib/_internal/compiler/implementation/helpers/trace.dart
diff --git a/sdk/lib/_internal/compiler/implementation/helpers/trace.dart b/sdk/lib/_internal/compiler/implementation/helpers/trace.dart
index 42c122acbec772dccad77b19f59a8f9a505508a0..b592972b36a923ba6f8464de0114d271dd16ddcc 100644
--- a/sdk/lib/_internal/compiler/implementation/helpers/trace.dart
+++ b/sdk/lib/_internal/compiler/implementation/helpers/trace.dart
@@ -13,8 +13,16 @@ part of dart2js.helpers;
  * returns [:true:] on the stack trace text. This can be used to filter the
  * printed stack traces based on their content. For instance only print stack
  * traces that contain specific paths.
+ *
+ * If [limit] is provided, the stack trace is limited to [limit] entries.
+ *
+ * If [throwOnPrint] is `true`, [message] will be thrown after the stack trace
+ * has been printed. Together with [condition] this can be used to discover
+ * unknown call-sites in tests by filtering known call-sites and throwning
+ * otherwise.
  */
-void trace(String message, {bool condition(String stackTrace), int limit}) {
+void trace(String message, {bool condition(String stackTrace), int limit,
+                            bool throwOnPrint: false}) {
   try {
     throw '';
   } catch (e, s) {
@@ -24,13 +32,16 @@ void trace(String message, {bool condition(String stackTrace), int limit}) {
       if (!condition(stackTrace)) return;
     }
     print('$message\n$stackTrace');
+    if (throwOnPrint) throw message;
   }
 }
 
 void traceAndReport(Compiler compiler, Spannable node, String message,
-                    {bool condition(String stackTrace), int limit}) {
+                    {bool condition(String stackTrace), int limit,
+                     bool throwOnPrint: false}) {
 
-  trace(message, condition: (String stackTrace) {
+  trace(message, limit: limit, throwOnPrint: throwOnPrint,
+        condition: (String stackTrace) {
     bool result = condition != null ? condition(stackTrace) : true;
     if (result) {
       reportHere(compiler, node, message);