[Sync] Initial implementation of foreign sessions suggestions provider.

components/ntp_snippets/features.h

Index: components/ntp_snippets/features.h
diff --git a/components/ntp_snippets/features.h b/components/ntp_snippets/features.h
index 655b99f0d8afc2047d93a32e2083cecbb3d1e248..48f6472c4e11b1cc05e965ed51fe361389476cd4 100644
--- a/components/ntp_snippets/features.h
+++ b/components/ntp_snippets/features.h
@@ -5,6 +5,8 @@
 #ifndef COMPONENTS_NTP_SNIPPETS_FEATURES_H_
 #define COMPONENTS_NTP_SNIPPETS_FEATURES_H_
 
+#include <string>
+
 #include "base/feature_list.h"
 
 namespace ntp_snippets {
@@ -15,6 +17,7 @@ extern const base::Feature kBookmarkSuggestionsFeature;
 extern const base::Feature kRecentOfflineTabSuggestionsFeature;
 extern const base::Feature kDownloadSuggestionsFeature;
 extern const base::Feature kPhysicalWebPageSuggestionsFeature;
+extern const base::Feature kForeignSessionsSuggestionsFeature;
 
 // Feature to allow the 'save to offline' option to appear in the snippets
 // context menu.
@@ -24,6 +27,10 @@ extern const base::Feature kSaveToOfflineFeature;
 // false, all the per-provider features are ignored.
 extern const base::Feature kContentSuggestionsFeature;
 
+int GetParamAsInt(const base::Feature& feature,
+                  const std::string& param_name,
+                  const int default_value);
+
 }  // namespace ntp_snippets
 
 #endif  // COMPONENTS_NTP_SNIPPETS_FEATURES_H_