services/ui: Get rid of IPC::ChannelHandle type converter

services/ui/gpu/gpu_service_mus.cc

Index: services/ui/gpu/gpu_service_mus.cc
diff --git a/services/ui/gpu/gpu_service_mus.cc b/services/ui/gpu/gpu_service_mus.cc
index fabbce31102148c3c3ec3a386442ad8ea366e432..16966490a30e5e2128f2a51943a6e269d811f886 100644
--- a/services/ui/gpu/gpu_service_mus.cc
+++ b/services/ui/gpu/gpu_service_mus.cc
@@ -42,9 +42,9 @@ const uint64_t kLocalGpuChannelClientTracingId = 1;
 
 void EstablishGpuChannelDone(
     int client_id,
-    const IPC::ChannelHandle* channel_handle,
+    IPC::ChannelHandle* channel_handle,
     const GpuServiceMus::EstablishGpuChannelCallback& callback) {
-  callback.Run(channel_handle ? client_id : -1, *channel_handle);
+  callback.Run(channel_handle ? client_id : -1, channel_handle);
 }
 }
 
@@ -76,7 +76,7 @@ void GpuServiceMus::EstablishGpuChannel(
   DCHECK(CalledOnValidThread());
 
   if (!gpu_channel_manager_) {
-    callback.Run(-1, IPC::ChannelHandle());
+    callback.Run(-1, nullptr);

[dcheng, 2016/08/18 00:06:01]

I would probably just throw a IPC::ChannelHandle on the stack here and pass the
address to the callback. Then we shouldn't need to handle the null case in
either of the callbacks, simplifying everything overall.

     return;
   }