Adds UMA to measure when the data reduction proxy via header is missing

components/data_reduction_proxy/browser/data_reduction_proxy_usage_stats.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/data_reduction_proxy/browser/data_reduction_proxy_usage_stats.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
+#include "base/prefs/pref_member.h"
 #include "components/data_reduction_proxy/common/data_reduction_proxy_headers.h"
 #include "net/base/net_errors.h"
+#include "net/http/http_response_headers.h"
+#include "net/http/http_status_code.h"
 #include "net/proxy/proxy_retry_info.h"
 #include "net/proxy/proxy_server.h"
 #include "net/proxy/proxy_service.h"
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_context.h"
 
 using base::MessageLoopProxy;
 using net::HostPortPair;
 using net::ProxyServer;
 using net::ProxyService;
@@ skipping 45 matching lines @@
     if (is_primary) {
       UMA_HISTOGRAM_ENUMERATION("DataReductionProxy.BypassTypePrimary",
                                 bypass_type, BYPASS_EVENT_TYPE_MAX);
     } else {
       UMA_HISTOGRAM_ENUMERATION("DataReductionProxy.BypassTypeFallback",
                                 bypass_type, BYPASS_EVENT_TYPE_MAX);
     }
   }
 }
 
+// static
+void DataReductionProxyUsageStats::DetectAndRecordMissingViaHeaderResponseCode(
+      bool is_primary,
+      const net::HttpResponseHeaders* headers) {
+  if (HasDataReductionProxyViaHeader(headers, NULL)) {
+    // The data reduction proxy via header is present, so don't record anything.
+    return;
+  }
+
+  if (is_primary) {
+    UMA_HISTOGRAM_SPARSE_SLOWLY(
+        "DataReductionProxy.MissingViaHeader.ResponseCode.Primary",
+        headers->response_code());
+  } else {
+    UMA_HISTOGRAM_SPARSE_SLOWLY(
+        "DataReductionProxy.MissingViaHeader.ResponseCode.Fallback",
+        headers->response_code());
+  }
+}
+
 DataReductionProxyUsageStats::DataReductionProxyUsageStats(
     DataReductionProxyParams* params,
     const scoped_refptr<MessageLoopProxy>& ui_thread_proxy)
     : data_reduction_proxy_params_(params),
       last_bypass_type_(BYPASS_EVENT_TYPE_MAX),
       triggering_request_(true),
       ui_thread_proxy_(ui_thread_proxy),
       successful_requests_through_proxy_count_(0),
       proxy_net_errors_count_(0),
       unavailable_(false) {
@@ skipping 49 matching lines @@
   if (!unavailable_callback_.is_null())
     unavailable_callback_.Run(unavailable);
 }
 
 void DataReductionProxyUsageStats::SetBypassType(
     DataReductionProxyBypassType type) {
   last_bypass_type_ = type;
   triggering_request_ = true;
 }
 
-void DataReductionProxyUsageStats::RecordBypassedBytesHistograms(
-    net::URLRequest& request,
+void DataReductionProxyUsageStats::RecordBytesHistograms(
+    net::URLRequest* request,
     const BooleanPrefMember& data_reduction_proxy_enabled,
     const net::ProxyConfig& data_reduction_proxy_config) {
-  int64 content_length = request.received_response_content_length();
+  RecordBypassedBytesHistograms(request, data_reduction_proxy_enabled,
+                                data_reduction_proxy_config);
+  RecordMissingViaHeaderBytes(request);
+}
+
+void DataReductionProxyUsageStats::RecordBypassedBytesHistograms(
+    net::URLRequest* request,
+    const BooleanPrefMember& data_reduction_proxy_enabled,
+    const net::ProxyConfig& data_reduction_proxy_config) {
+  int64 content_length = request->received_response_content_length();
 
   if (data_reduction_proxy_enabled.GetValue() &&
       !data_reduction_proxy_config.Equals(
-          request.context()->proxy_service()->config())) {
+          request->context()->proxy_service()->config())) {
     RecordBypassedBytes(last_bypass_type_,
                         DataReductionProxyUsageStats::MANAGED_PROXY_CONFIG,
                         content_length);
     return;
   }
 
-  if (data_reduction_proxy_params_->WasDataReductionProxyUsed(&request, NULL)) {
+  if (data_reduction_proxy_params_->WasDataReductionProxyUsed(request, NULL)) {
     RecordBypassedBytes(last_bypass_type_,
                         DataReductionProxyUsageStats::NOT_BYPASSED,
                         content_length);
     return;
   }
 
   if (data_reduction_proxy_enabled.GetValue() &&
-      request.url().SchemeIs(url::kHttpsScheme)) {
+      request->url().SchemeIs(url::kHttpsScheme)) {
     RecordBypassedBytes(last_bypass_type_,
                         DataReductionProxyUsageStats::SSL,
                         content_length);
     return;
   }
 
   if (data_reduction_proxy_enabled.GetValue() &&
       data_reduction_proxy_params_->IsBypassedByDataReductionProxyLocalRules(
-          request, data_reduction_proxy_config)) {
+          *request, data_reduction_proxy_config)) {
     RecordBypassedBytes(last_bypass_type_,
                         DataReductionProxyUsageStats::LOCAL_BYPASS_RULES,
                         content_length);
     return;
   }
 
   // Only record separate triggering request UMA for short, medium, and long
   // bypass events.
   if (triggering_request_ &&
      (last_bypass_type_ ==  BYPASS_EVENT_TYPE_SHORT ||
       last_bypass_type_ ==  BYPASS_EVENT_TYPE_MEDIUM ||
       last_bypass_type_ ==  BYPASS_EVENT_TYPE_LONG)) {
     std::string mime_type;
-    request.GetMimeType(&mime_type);
+    request->GetMimeType(&mime_type);
     // MIME types are named by <media-type>/<subtype>. Check to see if the
     // media type is audio or video. Only record when triggered by short bypass,
     // there isn't an audio or video bucket for medium or long bypasses.
     if (last_bypass_type_ ==  BYPASS_EVENT_TYPE_SHORT &&
        (mime_type.compare(0, 6, "audio/") == 0  ||
         mime_type.compare(0, 6, "video/") == 0)) {
       RecordBypassedBytes(last_bypass_type_,
                           DataReductionProxyUsageStats::AUDIO_VIDEO,
                           content_length);
       return;
     }
 
     RecordBypassedBytes(last_bypass_type_,
                         DataReductionProxyUsageStats::TRIGGERING_REQUEST,
                         content_length);
     triggering_request_ = false;
     return;
   }
 
   if (last_bypass_type_ != BYPASS_EVENT_TYPE_MAX) {
     RecordBypassedBytes(last_bypass_type_,
                         DataReductionProxyUsageStats::BYPASSED_BYTES_TYPE_MAX,
                         content_length);
     return;
   }
 
-  if (data_reduction_proxy_params_->AreDataReductionProxiesBypassed(request,
+  if (data_reduction_proxy_params_->AreDataReductionProxiesBypassed(*request,
                                                                     NULL)) {
     RecordBypassedBytes(last_bypass_type_,
                         DataReductionProxyUsageStats::NETWORK_ERROR,
                         content_length);
   }
 }
 
 void DataReductionProxyUsageStats::OnProxyFallback(
     const net::ProxyServer& bypassed_proxy,
     int net_error) {
@@ skipping 139 matching lines @@
               "Status503HttpServiceUnavailable",
               content_length);
           break;
         default:
           break;
       }
       break;
   }
 }
 
+void DataReductionProxyUsageStats::RecordMissingViaHeaderBytes(
+    URLRequest* request) {
+  // Responses that were served from cache should have been filtered out
+  // already.
+  DCHECK(!request->was_cached());
+
+  if (!data_reduction_proxy_params_->WasDataReductionProxyUsed(request, 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;
+  }
+
+  if (request->GetResponseCode() >= net::HTTP_BAD_REQUEST &&
+      request->GetResponseCode() < net::HTTP_INTERNAL_SERVER_ERROR) {
+    // Track 4xx responses that are missing via headers separately.
+    UMA_HISTOGRAM_COUNTS("DataReductionProxy.MissingViaHeader.Bytes.4xx",
+                         request->received_response_content_length());
+  } else {
+    UMA_HISTOGRAM_COUNTS("DataReductionProxy.MissingViaHeader.Bytes.Other",
+                         request->received_response_content_length());
+  }
+}
+
 }  // namespace data_reduction_proxy