Roll Observatory packages and add a roll script

packages/source_maps/.status

Index: packages/source_maps/.status
diff --git a/packages/source_maps/.status b/packages/source_maps/.status
new file mode 100644
index 0000000000000000000000000000000000000000..befa7ddc73550cf262bf400ca8be354780f34661
--- /dev/null
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+# Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+# Skip non-test files ending with "_test".
+packages/*: Skip
+*/packages/*: Skip
+*/*/packages/*: Skip
+*/*/*/packages/*: Skip
+*/*/*/*packages/*: Skip
+*/*/*/*/*packages/*: Skip
+
+# Only run tests from the build directory, since we don't care about the
+# difference between transformed an untransformed code.
+test/*: Skip
+
+[ $compiler == dart2js || $compiler == dart2dart ]
+build/test/vlq_test: RuntimeError # A VLQ test checks for large numbers that
+                                  # overflow in JS (numbers slightly larger than
+                                  # 32 bits where we do bitwise operations).