[NTP Snippets] Metrics: switch over known categories

components/ntp_snippets/content_suggestions_metrics.cc

Index: components/ntp_snippets/content_suggestions_metrics.cc
diff --git a/components/ntp_snippets/content_suggestions_metrics.cc b/components/ntp_snippets/content_suggestions_metrics.cc
index 5d4fbe169ad5a462da482bcc432b02bbbaa3b785..031a54ee0285a8901adfe35c796751b430f5653a 100644
--- a/components/ntp_snippets/content_suggestions_metrics.cc
+++ b/components/ntp_snippets/content_suggestions_metrics.cc
@@ -44,17 +44,27 @@ const char kHistogramMoreButtonClicked[] =
 const char kPerCategoryHistogramFormat[] = "%s.%s";
 
 std::string GetCategorySuffix(Category category) {
-  // TODO(treib): Find a way to produce a compile error if a known category
-  // isn't listed here.
-  if (category.IsKnownCategory(KnownCategories::RECENT_TABS))
-    return "RecentTabs";
-  if (category.IsKnownCategory(KnownCategories::DOWNLOADS))
-    return "Downloads";
-  if (category.IsKnownCategory(KnownCategories::BOOKMARKS))
-    return "Bookmarks";
-  if (category.IsKnownCategory(KnownCategories::ARTICLES))
-    return "Articles";
-  // All other categories go into a single "Experimental" bucket.
+  if (category.IsAnyKnownCategory()) {
+    KnownCategories known_category =
+        static_cast<KnownCategories>(category.id());
+    switch (known_category) {

[jkrcal, 2016/09/13 16:08:05]

Way better, thanks!

+      case KnownCategories::RECENT_TABS:
+        return "RecentTabs";
+      case KnownCategories::DOWNLOADS:
+        return "Downloads";
+      case KnownCategories::BOOKMARKS:
+        return "Bookmarks";
+      case KnownCategories::PHYSICAL_WEB_PAGES:
+        return "PhysicalWeb";
+      case KnownCategories::ARTICLES:
+        return "Articles";
+      case KnownCategories::LOCAL_CATEGORIES_COUNT:
+      case KnownCategories::REMOTE_CATEGORIES_OFFSET:
+        NOTREACHED();
+        break;
+    }
+  }
+  // All other (unknown) categories go into a single "Experimental" bucket.
   return "Experimental";
 }