Initialize data reduction proxy bypass stats on IO thread

components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc
index e64f585a05e3bb82922aba0f53f6a277832f82ba..70eb6211200b9e48c3c9d1fdc0b4a08abb4b7adc 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc
@@ -167,6 +167,9 @@ DataReductionProxyIOData::DataReductionProxyIOData(
 }
 
 DataReductionProxyIOData::~DataReductionProxyIOData() {
+  // Guaranteed to be destroyed on IO thread if the IO thread is still
+  // available at the time of destruction. If the IO thread is unavailable,
+  // then the destruction will happen on the UI thread.
 }
 
 void DataReductionProxyIOData::ShutdownOnUIThread() {
@@ -194,6 +197,7 @@ void DataReductionProxyIOData::SetDataReductionProxyService(
 void DataReductionProxyIOData::InitializeOnIOThread() {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
   config_->InitializeOnIOThread(basic_url_request_context_getter_.get());
+  bypass_stats_->InitializeOnIOThread();
   proxy_delegate_->InitializeOnIOThread();
   if (config_client_.get())
     config_client_->InitializeOnIOThread(url_request_context_getter_);