Implementation of PostTaskAndReply() in MessageLoopProxy and BrowserThread.

base/task.cc

Index: base/task.cc
diff --git a/base/task.cc b/base/task.cc
index 8c614734863fb5c8e34959dd2b00b4ac8c80e538..b770355c73f9122e6cbe03ac9162985a619a1f21 100644
--- a/base/task.cc
+++ b/base/task.cc
@@ -4,6 +4,9 @@
 
 #include "base/task.h"
 
+#include "base/bind.h"
+#include "base/message_loop_proxy.h"
+
 Task::Task() {
 }
 
@@ -63,4 +66,42 @@ bool TaskClosureAdapter::kTaskLeakingDefault = false;
 
 }  // namespace subtle
 
+namespace internal {
+
+PostTaskAndReplyRelay::PostTaskAndReplyRelay(
+    const tracked_objects::Location& from_here,
+    const Closure& task,
+    const Closure& reply)
+    : from_here_(from_here),
+      origin_loop_(MessageLoopProxy::CreateForCurrentThread()) {
+  task_ = task;
+  reply_ = reply;
+}
+
+PostTaskAndReplyRelay::~PostTaskAndReplyRelay() {
+  DCHECK(origin_loop_->BelongsToCurrentThread());
+  task_.Reset();
+  reply_.Reset();
+}
+
+void PostTaskAndReplyRelay::Run() {
+  task_.Run();
+  origin_loop_->PostTask(
+      from_here_,
+      Bind(&PostTaskAndReplyRelay::RunReplyAndSelfDestruct,
+           base::Unretained(this)));
+}
+
+void PostTaskAndReplyRelay::RunReplyAndSelfDestruct() {
+  DCHECK(origin_loop_->BelongsToCurrentThread());
+  task_.Reset();
+
+  reply_.Run();
+
+  // Cue mission impossible theme.
+  delete this;
+}
+
+}  // namespace internal
+
 }  // namespace base