[subresource_filter] Add debugging trace events around activation

components/subresource_filter/core/browser/subresource_filter_features.h

Index: components/subresource_filter/core/browser/subresource_filter_features.h
diff --git a/components/subresource_filter/core/browser/subresource_filter_features.h b/components/subresource_filter/core/browser/subresource_filter_features.h
index e075356c3c22d1ee67528b60f1d3e86020025b51..cf2e9d02df225d9c157ef0b2db187d430259688f 100644
--- a/components/subresource_filter/core/browser/subresource_filter_features.h
+++ b/components/subresource_filter/core/browser/subresource_filter_features.h
@@ -6,6 +6,7 @@
 #define COMPONENTS_SUBRESOURCE_FILTER_CORE_BROWSER_SUBRESOURCE_FILTER_FEATURES_H_
 
 #include <iosfwd>
+#include <memory>
 #include <vector>
 
 #include "base/feature_list.h"
@@ -16,6 +17,12 @@
 #include "components/subresource_filter/core/common/activation_list.h"
 #include "components/subresource_filter/core/common/activation_scope.h"
 
+namespace base {
+namespace trace_event {
+class TracedValue;
+}  // namespace trace_event
+}  // namespace base
+
 namespace subresource_filter {
 
 // Encapsulates a set of parameters that define how the subresource filter
@@ -102,6 +109,8 @@ struct Configuration {
   bool operator==(const Configuration& rhs) const;
   bool operator!=(const Configuration& rhs) const;
 
+  std::unique_ptr<base::trace_event::TracedValue> GetTracedValue() const;

[engedy, 2017/05/15 12:10:38]

nit: {As|To}TracedValue

[Charlie Harrison, 2017/05/15 15:14:22]

Renamed ToTracedValue.

+
   // Factory methods for preset configurations.
   //
   // To add a new preset: