Componentize OriginsSeenService & provide iOS factory.

components/navigation_metrics/origins_seen_service.h

Index: components/navigation_metrics/origins_seen_service.h
diff --git a/chrome/browser/tab_contents/origins_seen_service.h b/components/navigation_metrics/origins_seen_service.h
similarity index 77%
rename from chrome/browser/tab_contents/origins_seen_service.h
rename to components/navigation_metrics/origins_seen_service.h
index 55c417d5847a349fa68d122f54480939e3eceb0c..94e43305a1ddd0fb72fe2a3db841980d9fff0cb5 100644
--- a/chrome/browser/tab_contents/origins_seen_service.h
+++ b/components/navigation_metrics/origins_seen_service.h
@@ -2,13 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_TAB_CONTENTS_ORIGINS_SEEN_SERVICE_H_
-#define CHROME_BROWSER_TAB_CONTENTS_ORIGINS_SEEN_SERVICE_H_
+#ifndef COMPONENTS_NAVIGATION_METRICS_ORIGINS_SEEN_SERVICE_H_
+#define COMPONENTS_NAVIGATION_METRICS_ORIGINS_SEEN_SERVICE_H_
 
 #include "base/containers/mru_cache.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "url/origin.h"
 
+namespace navigation_metrics {
+
 class OriginsSeenService : public KeyedService {
  public:
   OriginsSeenService();
@@ -26,4 +28,6 @@ class OriginsSeenService : public KeyedService {
   base::MRUCache<url::Origin, bool> origins_seen_;
 };
 
-#endif  // CHROME_BROWSER_TAB_CONTENTS_ORIGINS_SEEN_SERVICE_H_
+}  // namespace navigation_metrics
+
+#endif  // COMPONENTS_NAVIGATION_METRICS_ORIGINS_SEEN_SERVICE_H_