Remove ShutdownIPCSupportAndWaitForNoChannels.

mojo/edk/system/raw_channel_win.cc

Index: mojo/edk/system/raw_channel_win.cc
diff --git a/mojo/edk/system/raw_channel_win.cc b/mojo/edk/system/raw_channel_win.cc
index fa968a4594d396d591e185faf6fd102c1b8cdb41..51a8e684e97d3a5ef6ebfd69d4530be580ec9359 100644
--- a/mojo/edk/system/raw_channel_win.cc
+++ b/mojo/edk/system/raw_channel_win.cc
@@ -124,6 +124,7 @@ class RawChannelWin final : public RawChannel {
     RawChannelIOHandler(RawChannelWin* owner,
                         ScopedPlatformHandle handle)
         : handle_(handle.Pass()),
+          io_task_runner_(internal::g_io_thread_task_runner),
           owner_(owner),
           suppress_self_destruct_(false),
           pending_read_(false),
@@ -465,7 +466,7 @@ class RawChannelWin final : public RawChannel {
       // that that is always a pointer to a valid RawChannelIOHandler.
       RawChannelIOHandler* that = static_cast<RawChannelIOHandler*>(param);
       that->read_event_signalled_ = true;
-      internal::g_io_thread_task_runner->PostTask(
+      that->io_task_runner_->PostTask(
           FROM_HERE,
           base::Bind(&RawChannelIOHandler::OnObjectSignaled,
                      that->this_weakptr_, that->read_event_.Get()));
@@ -477,7 +478,7 @@ class RawChannelWin final : public RawChannel {
       // that that is always a pointer to a valid RawChannelIOHandler.
       RawChannelIOHandler* that = static_cast<RawChannelIOHandler*>(param);
       that->write_event_signalled_ = true;
-      internal::g_io_thread_task_runner->PostTask(
+      that->io_task_runner_->PostTask(
           FROM_HERE,
           base::Bind(&RawChannelIOHandler::OnObjectSignaled,
                      that->this_weakptr_, that->write_event_.Get()));
@@ -485,6 +486,10 @@ class RawChannelWin final : public RawChannel {
 
     ScopedPlatformHandle handle_;
 
+    // We cache this because ReadCompleted and WriteCompleted might get fired
+    // after ShutdownIPCSupport is called.
+    scoped_refptr<base::TaskRunner> io_task_runner_;
+
     // |owner_| is reset on the I/O thread under |owner_->write_lock()|.
     // Therefore, it may be used on any thread under lock; or on the I/O thread
     // without locking.