Add experimental feature info to certificate reports

components/certificate_reporting/cert_logger.proto

Index: components/certificate_reporting/cert_logger.proto
diff --git a/components/certificate_reporting/cert_logger.proto b/components/certificate_reporting/cert_logger.proto
index 13dfda17f5fcfecb01bcfaa8701d1acce1e63137..fed2956db8e4eb2f7bfe3d901c504a0c0d86c9bc 100644
--- a/components/certificate_reporting/cert_logger.proto
+++ b/components/certificate_reporting/cert_logger.proto
@@ -44,6 +44,23 @@ message CertLoggerInterstitialInfo {
   optional bool overridable = 3;
 }
 
+// Contains information about features that are enabled/disabled that
+// might affect certificate validation.
+message CertLoggerFeatureInfo {
+  // The name of the feature.
+  optional string feature = 1;
+  // True if the feature is enabled for the user sending the report.
+  optional bool enabled = 2;
+  // A serialized JSON dictionary of experiment parameters for the feature.
+
+  // An experiment parameter associated with this feature.
+  message Parameter {
+    optional string name = 1;
+    optional string value = 2;
+  };
+  repeated Parameter params = 3;
+}
+
 message CertLoggerRequest {
   // The hostname being accessed (required as the cert could be valid for
   // multiple hosts, e.g. a wildcard or a SubjectAltName.
@@ -98,4 +115,8 @@ message CertLoggerRequest {
   // validation library built a trusted chain (i.e. the Chrome net stack set the
   // error, not the library).
   optional bool is_issued_by_known_root = 9;
+
+  // Information about features that were enabled or disabled for the
+  // user that might affect certificate validation.
+  repeated CertLoggerFeatureInfo features_info = 10;
 };