update_engine: fixed remaining linter and some spelling errors

Fixed remaining errors from cpplint as well as some spelling errors
mostly in comments.

BUG=None
TEST=FEATURES=test emerge-link update_engine

Change-Id: I484988ab846ac5a3c68c016ddccfb247f225ec27
Reviewed-on: https://chromium-review.googlesource.com/208897
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Commit-Queue: Alex Vakulenko <avakulenko@chromium.org>
Tested-by: Alex Vakulenko <avakulenko@chromium.org>
diff --git a/update_manager/chromeos_policy.h b/update_manager/chromeos_policy.h
index 9c9fe9d..c954f9d 100644
--- a/update_manager/chromeos_policy.h
+++ b/update_manager/chromeos_policy.h
@@ -112,9 +112,9 @@
   // number of failures associated with that URL; and |download_url_error_codes|
   // the list of failures occurring since the latest evaluation.
   //
-  // Upon successly deciding a URL to use, returns |EvalStatus::kSucceeded| and
-  // writes the current URL index and the number of failures associated with it
-  // in |result|. Otherwise, returns |EvalStatus::kFailed|.
+  // Upon successfully deciding a URL to use, returns |EvalStatus::kSucceeded|
+  // and writes the current URL index and the number of failures associated with
+  // it in |result|. Otherwise, returns |EvalStatus::kFailed|.
   EvalStatus UpdateDownloadUrl(EvaluationContext* ec, State* state,
                                std::string* error,
                                UpdateDownloadUrlResult* result,