Add Observatory to sky dart_controller

sky/tools/webkitpy/layout_tests/controllers/single_test_runner.py

Index: sky/tools/webkitpy/layout_tests/controllers/single_test_runner.py
diff --git a/sky/tools/webkitpy/layout_tests/controllers/single_test_runner.py b/sky/tools/webkitpy/layout_tests/controllers/single_test_runner.py
index 31d4d8cda39c0e193506d672bb864387f8e2a25d..5273d7ecb2651155b096707e0e90eab46c039c5d 100644
--- a/sky/tools/webkitpy/layout_tests/controllers/single_test_runner.py
+++ b/sky/tools/webkitpy/layout_tests/controllers/single_test_runner.py
@@ -307,6 +307,8 @@ class SingleTestRunner(object):
             failures.append(test_failures.FailureMissingAudio())
         return failures
 
+    _filter_observatory_messages = re.compile(r"^CONSOLE: Observatory listening on.*\n", re.MULTILINE)
+
     def _get_normalized_output_text(self, output):
         """Returns the normalized text output, i.e. the output in which
         the end-of-line characters are normalized to "\n"."""
@@ -314,7 +316,9 @@ class SingleTestRunner(object):
         # changed to "\r\n" by our system (Python/Cygwin), resulting in
         # "\r\r\n", when, in fact, we wanted to compare the text output with
         # the normalized text expectation files.
-        return output.replace("\r\r\n", "\r\n").replace("\r\n", "\n")
+        normalized_lines = output.replace("\r\r\n", "\r\n").replace("\r\n", "\n")
+        normalized_lines = re.sub(self._filter_observatory_messages, r"", normalized_lines)
+        return normalized_lines
 
     # FIXME: This function also creates the image diff. Maybe that work should
     # be handled elsewhere?