Dev compiler debugger related tweaks.

tests/lib_strong/html/debugger_test_golden.txt

Index: tests/lib_strong/html/debugger_test_golden.txt
diff --git a/tests/lib_strong/html/debugger_test_golden.txt b/tests/lib_strong/html/debugger_test_golden.txt
index 951a96218737ba264502f5441de8692281b17366..fa5a248e25562f4e1553b9df14e2c901aec1812f 100644
--- a/tests/lib_strong/html/debugger_test_golden.txt
+++ b/tests/lib_strong/html/debugger_test_golden.txt
@@ -5889,7 +5889,13 @@ Value:
 -----------------------------------
 Test: Test library Module header
 Value:
-null
+[
+    "span",
+    {
+        "style": "background-color: #d9edf7;"
+    },
+    "Library Module: lib/html/debugger_test"

[Jacob, 2017/04/12 18:24:42]

Correctly identified this was a Dart Library module instead of a JS object.

+]
 -----------------------------------
 Test: Test library Module body
 Value:
@@ -8814,4 +8820,3 @@ Value:
     ]
 ]
 -----------------------------------
-