Add DataReductionProxyExperimentsStats and UMA for measuring potentially non-compressed bytes.

components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
index 9a66acdfb74cdbd81f0fee8cb1e945a0effbc4f4..706f1729d545ddddcb4a06db53137923cb5ded05 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
@@ -12,6 +12,7 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_configurator.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_experiments_stats.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
@@ -76,7 +77,8 @@ DataReductionProxyNetworkDelegate::DataReductionProxyNetworkDelegate(
     scoped_ptr<net::NetworkDelegate> network_delegate,
     DataReductionProxyConfig* config,
     DataReductionProxyRequestOptions* request_options,
-    const DataReductionProxyConfigurator* configurator)
+    const DataReductionProxyConfigurator* configurator,
+    DataReductionProxyExperimentsStats* experiments_stats)
     : LayeredNetworkDelegate(network_delegate.Pass()),
       received_content_length_(0),
       original_content_length_(0),
@@ -84,9 +86,11 @@ DataReductionProxyNetworkDelegate::DataReductionProxyNetworkDelegate(
       data_reduction_proxy_bypass_stats_(nullptr),
       data_reduction_proxy_request_options_(request_options),
       data_reduction_proxy_io_data_(nullptr),
-      configurator_(configurator) {
+      configurator_(configurator),
+      experiments_stats_(experiments_stats) {
   DCHECK(data_reduction_proxy_config_);
   DCHECK(data_reduction_proxy_request_options_);
+  DCHECK(experiments_stats_);
 }
 
 DataReductionProxyNetworkDelegate::~DataReductionProxyNetworkDelegate() {
@@ -185,6 +189,9 @@ void DataReductionProxyNetworkDelegate::OnCompletedInternal(
     RecordContentLengthHistograms(received_content_length,
                                   original_content_length,
                                   freshness_lifetime);
+    experiments_stats_->RecordBytes(request->request_time(), request_type,
+                                    received_content_length,
+                                    original_content_length);
 
     if (data_reduction_proxy_io_data_ && data_reduction_proxy_bypass_stats_) {
       data_reduction_proxy_bypass_stats_->RecordBytesHistograms(