Add experimental feature info to certificate reports

components/certificate_reporting/error_report.h

Index: components/certificate_reporting/error_report.h
diff --git a/components/certificate_reporting/error_report.h b/components/certificate_reporting/error_report.h
index 0200dcd4304be9f3230a80a0e4d327c02f46f02d..cd36381c90fd5ad339f689d7c61a15a3ac08d138 100644
--- a/components/certificate_reporting/error_report.h
+++ b/components/certificate_reporting/error_report.h
@@ -5,9 +5,13 @@
 #ifndef COMPONENTS_CERTIFICATE_REPORTING_CERTIFICATE_ERROR_REPORT_H_
 #define COMPONENTS_CERTIFICATE_REPORTING_CERTIFICATE_ERROR_REPORT_H_
 
+#include <map>
 #include <memory>
 #include <string>
 
+namespace base {
+struct Feature;
+}  // namespace base
 
 namespace net {
 class SSLInfo;
@@ -64,6 +68,13 @@ class ErrorReport {
   // Gets the hostname to which this report corresponds.
   const std::string& hostname() const;
 
+  // Populates the report with information about the given feature,
+  // including whether it is enabled or disabled and its experiment
+  // parameters.
+  void AddFeature(const std::string& feature_name,
+                  bool enabled,
+                  const std::map<std::string, std::string>& params);

[jwd, 2016/11/03 15:15:34]

Hmmm, I actually liked passing the feature itself more. I was thinking of
passing a list of the param keys, letting AddFeature get the values based on the
given feature. Thoughts?

+
  private:
   std::unique_ptr<CertLoggerRequest> cert_report_;
 };