Move session network stats from IO to UI

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 d9b71e11ed5378a14016bdc8752693506990172c..245c681e164a08d24c82cca7cc860aa3ad50f3ea 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
@@ -102,14 +102,16 @@ class DataReductionProxyIOData : public DataReductionProxyEventStorageDelegate {
   // Sets Lo-Fi mode off in |config_|.
   void SetLoFiModeOff();
 
-  // Bridge methods to safely call to the UI thread objects.
-  void UpdateContentLengths(
+  // Bridge methods to safely call to the UI thread objects. Virtual for
+  // testing.
+  virtual void UpdateContentLengths(
       int64_t data_used,
       int64_t original_size,
       bool data_reduction_proxy_enabled,
       DataReductionProxyRequestType request_type,
       const scoped_refptr<DataUseGroup>& data_usage_source,
       const std::string& mime_type);
+
   void SetLoFiModeActiveOnMainFrame(bool lo_fi_mode_active);
 
   // Overrides of DataReductionProxyEventStorageDelegate. Bridges to the UI