Fix a bad merge in pkg/stack_trace.

pkg/stack_trace/lib/src/trace.dart

Index: pkg/stack_trace/lib/src/trace.dart
diff --git a/pkg/stack_trace/lib/src/trace.dart b/pkg/stack_trace/lib/src/trace.dart
index 46baadaa58b6fc6c8f5d2cd24738f2a236993b5d..19f0a12c52f307c111fc29999eabcec1b674cc2b 100644
--- a/pkg/stack_trace/lib/src/trace.dart
+++ b/pkg/stack_trace/lib/src/trace.dart
@@ -82,9 +82,9 @@ class Trace implements StackTrace {
   factory Trace.parse(String trace) {
     try {
       if (trace.isEmpty) return new Trace(<Frame>[]);
-      if (trace.startsWith("Error\n")) return new Trace.parseV8(trace);
+      if (trace.contains(_v8Trace)) return new Trace.parseV8(trace);
       // Valid Safari traces are a superset of valid Firefox traces.
-      if (trace.contains(_firefoxTrace)) return new Trace.parseFirefox(trace);
+      if (trace.contains(_firefoxTrace)) return new Trace.parseSafari(trace);
       if (trace.contains(_friendlyTrace)) return new Trace.parseFriendly(trace);
 
       // Default to parsing the stack trace as a VM trace. This is also hit on