Componentize omnibox_edit_unittest.cc

This CL cleans omnibox_edit_unittest.cc of //chrome and //content dependencies
and moves it to live next to the production code that it is testing.

Review URL: https://codereview.chromium.org/1637883002

Cr-Commit-Position: refs/heads/master@{#372682}
diff --git a/components/omnibox/browser/autocomplete_classifier.cc b/components/omnibox/browser/autocomplete_classifier.cc
index cd60893..be346c53 100644
--- a/components/omnibox/browser/autocomplete_classifier.cc
+++ b/components/omnibox/browser/autocomplete_classifier.cc
@@ -47,6 +47,10 @@
   DCHECK(!controller_.get());
 }
 
+void AutocompleteClassifier::Shutdown() {
+  controller_.reset();
+}
+
 void AutocompleteClassifier::Classify(
     const base::string16& text,
     bool prefer_keyword,
@@ -73,7 +77,3 @@
   if (alternate_nav_url)
     *alternate_nav_url = result.alternate_nav_url();
 }
-
-void AutocompleteClassifier::Shutdown() {
-  controller_.reset();
-}