Control data saver pingback reporting fraction with protobuf

components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h
index edd83e2bec69a3f488653d8adb17666ad406b1fc..e53cd86f3ce64a9f97db3c67ec10a06ec0c27d01 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h
@@ -114,20 +114,24 @@ class DataReductionProxyIOData : public DataReductionProxyEventStorageDelegate {
   void AddEnabledEvent(std::unique_ptr<base::Value> event,
                        bool enabled) override;
   void AddEventAndSecureProxyCheckState(std::unique_ptr<base::Value> event,
                                         SecureProxyCheckState state) override;
   void AddAndSetLastBypassEvent(std::unique_ptr<base::Value> event,
                                 int64_t expiration_ticks) override;
 
   // Returns true if the Data Reduction Proxy is enabled and false otherwise.
   bool IsEnabled() const;
 
+  // Changes the reporting fraction for the pingback service to
+  // |pingback_reporting_fraction|. Overridden in testing.
+  virtual void SetPingbackReportingFraction(float pingback_reporting_fraction);
+
   // Various accessor methods.
   DataReductionProxyConfigurator* configurator() const {
     return configurator_.get();
   }
 
   DataReductionProxyConfig* config() const {
     return config_.get();
   }
 
   DataReductionProxyEventCreator* event_creator() const {