Wrapped data reduction proxy initialization into its own class

components/data_reduction_proxy/core/browser/data_reduction_proxy_usage_stats.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_usage_stats.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_usage_stats.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_usage_stats.cc
index a755e6de5983cddc1b8b5933a903a769ef98e271..37f1ce1df15bca5099a6deb81ecf97668a185b97 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_usage_stats.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_usage_stats.cc
@@ -6,10 +6,11 @@
 
 #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 "base/single_thread_task_runner.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_settings.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "net/base/load_flags.h"
@@ -102,11 +103,13 @@ void DataReductionProxyUsageStats::DetectAndRecordMissingViaHeaderResponseCode(
 
 DataReductionProxyUsageStats::DataReductionProxyUsageStats(
     DataReductionProxyParams* params,
-    const scoped_refptr<MessageLoopProxy>& ui_thread_proxy)
+    DataReductionProxySettings* settings,
+    const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner)
     : data_reduction_proxy_params_(params),
+      settings_(settings),
       last_bypass_type_(BYPASS_EVENT_TYPE_MAX),
       triggering_request_(true),
-      ui_thread_proxy_(ui_thread_proxy),
+      ui_task_runner_(ui_task_runner),
       successful_requests_through_proxy_count_(0),
       proxy_net_errors_count_(0),
       unavailable_(false) {
@@ -174,7 +177,7 @@ void DataReductionProxyUsageStats::NotifyUnavailabilityIfChanged() {
           successful_requests_through_proxy_count_ <=
               kMaxSuccessfulRequestsWhenUnavailable);
   if (prev_unavailable != unavailable_) {
-    ui_thread_proxy_->PostTask(FROM_HERE, base::Bind(
+    ui_task_runner_->PostTask(FROM_HERE, base::Bind(
         &DataReductionProxyUsageStats::NotifyUnavailabilityOnUIThread,
         base::Unretained(this),
         unavailable_));
@@ -183,9 +186,9 @@ void DataReductionProxyUsageStats::NotifyUnavailabilityIfChanged() {
 
 void DataReductionProxyUsageStats::NotifyUnavailabilityOnUIThread(
     bool unavailable) {
-  DCHECK(ui_thread_proxy_->BelongsToCurrentThread());
-  if (!unavailable_callback_.is_null())
-    unavailable_callback_.Run(unavailable);
+  DCHECK(ui_task_runner_->BelongsToCurrentThread());
+  if (settings_)
+    settings_->SetUnreachable(unavailable);
 }
 
 void DataReductionProxyUsageStats::SetBypassType(