Use ArgumentError.value in more places in js_lib.

sdk/lib/_internal/compiler/js_lib/string_helper.dart

Index: sdk/lib/_internal/compiler/js_lib/string_helper.dart
diff --git a/sdk/lib/_internal/compiler/js_lib/string_helper.dart b/sdk/lib/_internal/compiler/js_lib/string_helper.dart
index 0206fe197a9e0605f79ed756fc63f8f7f854a8a4..51b696bc708c5b5fb401cf72de21a19fb9a55553 100644
--- a/sdk/lib/_internal/compiler/js_lib/string_helper.dart
+++ b/sdk/lib/_internal/compiler/js_lib/string_helper.dart
@@ -145,10 +145,11 @@ stringReplaceAllFuncUnchecked(receiver, pattern, onMatch, onNonMatch) {
     return stringReplaceAllStringFuncUnchecked(receiver, pattern,
                                                onMatch, onNonMatch);
   }
-  // Pattern test here is indistingishable from at the top of the method but we
-  // don't need to do it on the `pattern is String` path.
+  // Placing the Pattern test here is indistingishable from placing it at the
+  // top of the method but it saves an extra check on the `pattern is String`
+  // path.
   if (pattern is! Pattern) {
-    throw new ArgumentError("${pattern} is not a Pattern");
+    throw new ArgumentError.value(pattern, 'pattern', 'is not a Pattern');
   }
   StringBuffer buffer = new StringBuffer();
   int startIndex = 0;