dbus: adding PostTaskToDBusThreadAndReply

This CL only adds a util method.

BUG=172821
TEST=unittests
R=satorux@chromium.org

Review URL: https://codereview.chromium.org/14985008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@198876 0039d316-1c4b-4281-b951-d872f2087c98

dbus/bus.cc

@@ -775,6 +775,24 @@ void Bus::ProcessAllIncomingDataIfAny() {
   }
 }
 
+void Bus::PostTaskToDBusThreadAndReply(
+    const tracked_objects::Location& from_here,
+    const base::Closure& task,
+    const base::Closure& reply) {
+  AssertOnOriginThread();
+
+  if (dbus_task_runner_.get()) {
+    if (!dbus_task_runner_->PostTaskAndReply(from_here, task, reply)) {
+      LOG(WARNING) << "Failed to post a task to the D-Bus thread message loop";
+    }
+  } else {
+    DCHECK(origin_task_runner_.get());
+    if (!origin_task_runner_->PostTaskAndReply(from_here, task, reply)) {
+      LOG(WARNING) << "Failed to post a task to the origin message loop";
+    }
+  }
+}
+
 void Bus::PostTaskToOriginThread(const tracked_objects::Location& from_here,
                                  const base::Closure& task) {
   DCHECK(origin_task_runner_.get());

dbus/bus.h

@@ -511,6 +511,13 @@ class CHROME_DBUS_EXPORT Bus : public base::RefCountedThreadSafe<Bus> {
   // BLOCKING CALL.
   virtual void UnregisterObjectPath(const ObjectPath& object_path);
 
+  // Posts |task| to the task runner of the D-Bus thread. On completion, |reply|
+  // is posted to the origin thread.
+  virtual void PostTaskToDBusThreadAndReply(
+      const tracked_objects::Location& from_here,
+      const base::Closure& task,
+      const base::Closure& reply);
+
   // Posts the task to the task runner of the thread that created the bus.
   virtual void PostTaskToOriginThread(
       const tracked_objects::Location& from_here,