Encouraging ThreadTaskRunnerHandle usage in net/dns module

net/dns/host_resolver_impl.cc

Index: net/dns/host_resolver_impl.cc
diff --git a/net/dns/host_resolver_impl.cc b/net/dns/host_resolver_impl.cc
index bd6e43198dca94319fe32227f5bc89475634f90a..e241e564eb2f205ddbcb09e44a0a9f68e7d4365b 100644
--- a/net/dns/host_resolver_impl.cc
+++ b/net/dns/host_resolver_impl.cc
@@ -21,13 +21,14 @@
 #include "base/compiler_specific.h"
 #include "base/debug/debugger.h"
 #include "base/debug/stack_trace.h"
-#include "base/message_loop/message_loop_proxy.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/profiler/scoped_tracker.h"
+#include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/thread_task_runner_handle.h"
 #include "base/threading/worker_pool.h"
 #include "base/time/time.h"
 #include "base/values.h"
@@ -573,7 +574,7 @@ class HostResolverImpl::ProcTask
       : key_(key),
         params_(params),
         callback_(callback),
-        origin_loop_(base::MessageLoopProxy::current()),
+        origin_loop_(base::ThreadTaskRunnerHandle::Get()),
         attempt_number_(0),
         completed_attempt_number_(0),
         completed_attempt_error_(ERR_UNEXPECTED),
@@ -904,7 +905,7 @@ class HostResolverImpl::ProcTask
   Callback callback_;
 
   // Used to post ourselves onto the origin thread.
-  scoped_refptr<base::MessageLoopProxy> origin_loop_;
+  scoped_refptr<base::SingleThreadTaskRunner> origin_loop_;

[asanka, 2015/05/14 04:06:36]

Could you rename this to task_runner_ and document it as the task runner for the
origin thread?

[anujsharma, 2015/05/14 04:39:40]

Done.

 
   // Keeps track of the number of attempts we have made so far to resolve the
   // host. Whenever we start an attempt to resolve the host, we increase this