Fix Closure Compiler's compile.py error checking

third_party/closure_compiler/compile2.py

Index: third_party/closure_compiler/compile2.py
diff --git a/third_party/closure_compiler/compile2.py b/third_party/closure_compiler/compile2.py
index dfd22cfe26700adbec40eaeb000337cc5a474319..fb0ced106c531d83b1310dfac9e748720e176531 100755
--- a/third_party/closure_compiler/compile2.py
+++ b/third_party/closure_compiler/compile2.py
@@ -266,20 +266,19 @@ class Checker(object):
 
     processed_runner_args = ["--%s" % arg for arg in runner_args or []]
     processed_runner_args += ["--compiler-args-file=%s" % args_file]
-    _, stderr = self._run_jar(self._runner_jar, processed_runner_args)
+    return_code, stderr = self._run_jar(self._runner_jar, processed_runner_args)
 
     errors = stderr.strip().split("\n\n")
     maybe_summary = errors.pop()
 
-    summary = re.search("(?P<error_count>\d+).*error.*warning", maybe_summary)
-    if summary:
+    if return_code == 0:
       self._log_debug("Summary: %s" % maybe_summary)
     else:
-      # Not a summary. Running the jar failed. Bail.
+      # Running the jar failed.
       self._log_error(stderr)
       self._nuke_temp_files()
-      sys.exit(1)
 
+    summary = re.search("(?P<error_count>\d+).*error.*warning", maybe_summary)
     if summary.group('error_count') != "0" and out_file:
       if os.path.exists(out_file):
         os.remove(out_file)