Metrics for tracking Safe Browsing hit patterns for the Safe Browsing lists Subresource Filter.

components/subresource_filter/core/common/activation_list.h

Index: components/subresource_filter/core/common/activation_list.h
diff --git a/components/subresource_filter/core/common/activation_list.h b/components/subresource_filter/core/common/activation_list.h
index 87b6408de09a4b5b09b1593ae5e503fe1cc44c7e..c24118ba7158e1c13f3c082e1775eb67e39fbeb1 100644
--- a/components/subresource_filter/core/common/activation_list.h
+++ b/components/subresource_filter/core/common/activation_list.h
@@ -5,6 +5,8 @@
 #ifndef COMPONENTS_SUBRESOURCE_FILTER_CORE_COMMON_ACTIVATION_LIST_H_
 #define COMPONENTS_SUBRESOURCE_FILTER_CORE_COMMON_ACTIVATION_LIST_H_
 
+#include <iosfwd>
+
 namespace subresource_filter {
 
 enum class ActivationList {
@@ -14,6 +16,9 @@ enum class ActivationList {
   LAST = PHISHING_INTERSTITIAL,
 };
 
+// For logging use only.
+std::ostream& operator<<(std::ostream& os, const ActivationList& type);
+
 }  // namespace subresource_filter
 
 #endif  // COMPONENTS_SUBRESOURCE_FILTER_CORE_COMMON_ACTIVATION_LIST_H_