Fix a variety of service protocol bugs.

runtime/vm/unit_test.h

Index: runtime/vm/unit_test.h
diff --git a/runtime/vm/unit_test.h b/runtime/vm/unit_test.h
index 1edeb159cc96e0e7d736d4aada6abed4ad2fd324..d4853e4ca1e3f5f17f0db309d32bcab46b141eb4 100644
--- a/runtime/vm/unit_test.h
+++ b/runtime/vm/unit_test.h
@@ -521,6 +521,24 @@ class CompilerTest : public AllStatic {
     }                                                                          \
   } while (0)
 
+
+// Elide a substring which starts with some prefix and ends with a ".
+//
+// This is used to remove non-deterministic or fragile substrings from
+// JSON output.
+//
+// For example:
+//
+//    prefix = "classes"
+//    in = "\"id\":\"classes/46\""
+//
+// Yields:
+//
+//    out = "\"id\":\"\""
+//
+void ElideJSONSubstring(const char* prefix, const char* in, char* out);
+
+
 }  // namespace dart
 
 #endif  // VM_UNIT_TEST_H_