Bypass DRP if a redirect cycle is detected

components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc
index 3aa6b85d42d790a99c0a7436f4bad587d4f719cd..718c1f234b06545e9035e04ea78503e606db26b0 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc
@@ -100,8 +100,8 @@ void DataReductionProxyBypassStats::RecordDataReductionProxyBypassInfo(
 // static
 void DataReductionProxyBypassStats::DetectAndRecordMissingViaHeaderResponseCode(
     bool is_primary,
-    const net::HttpResponseHeaders* headers) {
-  if (HasDataReductionProxyViaHeader(headers, NULL)) {
+    const net::HttpResponseHeaders& headers) {
+  if (HasDataReductionProxyViaHeader(headers, nullptr)) {
     // The data reduction proxy via header is present, so don't record anything.
     return;
   }
@@ -109,11 +109,11 @@ void DataReductionProxyBypassStats::DetectAndRecordMissingViaHeaderResponseCode(
   if (is_primary) {
     UMA_HISTOGRAM_SPARSE_SLOWLY(
         "DataReductionProxy.MissingViaHeader.ResponseCode.Primary",
-        headers->response_code());
+        headers.response_code());
   } else {
     UMA_HISTOGRAM_SPARSE_SLOWLY(
         "DataReductionProxy.MissingViaHeader.ResponseCode.Fallback",
-        headers->response_code());
+        headers.response_code());
   }
 }
 
@@ -385,7 +385,7 @@ void DataReductionProxyBypassStats::RecordMissingViaHeaderBytes(
 
   if (!data_reduction_proxy_config_->WasDataReductionProxyUsed(&request,
                                                                NULL) ||
-      HasDataReductionProxyViaHeader(request.response_headers(), NULL)) {
+      HasDataReductionProxyViaHeader(*request.response_headers(), NULL)) {
     // Only track requests that used the data reduction proxy and had responses
     // that were missing the data reduction proxy via header.
     return;
@@ -537,6 +537,11 @@ void DataReductionProxyBypassStats::RecordBypassedBytes(
               "Status503HttpServiceUnavailable",
               content_length);
           break;
+        case BYPASS_EVENT_TYPE_URL_REDIRECT_CYCLE:
+          UMA_HISTOGRAM_COUNTS(
+              "DataReductionProxy.BypassedBytes.URLRedirectCycle",
+              content_length);
+          break;
         default:
           break;
       }