[omnibox] Linting

I made a lint pass on components/omnibox/browser, so that we could
lint future changes and not see this old noise.

Bug: 
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Ie9502502ac4a83ef6ed02cb536f3590339a236ab
Reviewed-on: https://chromium-review.googlesource.com/740101
Reviewed-by: Justin Donnelly <[email protected]>
Reviewed-by: Rohit Rao (ping after 24h) <[email protected]>
Commit-Queue: Kevin Bailey <[email protected]>
Cr-Commit-Position: refs/heads/master@{#512272}
diff --git a/components/omnibox/browser/suggestion_answer_unittest.cc b/components/omnibox/browser/suggestion_answer_unittest.cc
index ff8395f..d0a3553f 100644
--- a/components/omnibox/browser/suggestion_answer_unittest.cc
+++ b/components/omnibox/browser/suggestion_answer_unittest.cc
@@ -4,6 +4,8 @@
 
 #include "components/omnibox/browser/suggestion_answer.h"
 
+#include <algorithm>
+
 #include "base/json/json_reader.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"