Set exp id in the CP header if user is in Lo-Fi control.

components/data_reduction_proxy/core/browser/data_reduction_proxy_config_test_utils.h

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_config_test_utils.h
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_test_utils.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_test_utils.h
index 59ab69316b362a8cee64f113ca8e8e01d08eb752..d709461213cef2082cedc1b7ee336db9512d023a 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_test_utils.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_test_utils.h
@@ -75,6 +75,11 @@ class TestDataReductionProxyConfig : public DataReductionProxyConfig {
   // Allows tests to set the session as part of Lo-Fi enabled field trial.
   void SetIncludedInLoFiEnabledFieldTrial(bool included_in_lofi_enabled);
 
+  bool IsIncludedInLoFiControlFieldTrial() const override;
+
+  // Allows tests to set the session as part of Lo-Fi control field trial.
+  void SetIncludedInLoFiControlFieldTrial(bool included_in_lofi_control);
+
   // Allows tests to mark the network as prohibitively slow.
   void SetNetworkProhibitivelySlow(bool network_quality_prohibitively_slow);
 
@@ -91,6 +96,9 @@ class TestDataReductionProxyConfig : public DataReductionProxyConfig {
   // True if this session is part of Auto Lo-Fi enabled field trial.
   bool auto_lofi_enabled_group_;
 
+  // True if this session is part of Auto Lo-Fi control field trial.
+  bool auto_lofi_control_group_;
+
   // True if network quality is slow enough to turn Auto Lo-Fi ON.
   bool network_quality_prohibitively_slow_;
 };