Use ChannelMojo for NaCl PPAPI channels.

components/nacl/browser/nacl_process_host.cc

Index: components/nacl/browser/nacl_process_host.cc
diff --git a/components/nacl/browser/nacl_process_host.cc b/components/nacl/browser/nacl_process_host.cc
index 633bace8b53ab92d7133240f4ae2bab9262345c8..c038521962e93ff8c709dccca2316892547ed7d0 100644
--- a/components/nacl/browser/nacl_process_host.cc
+++ b/components/nacl/browser/nacl_process_host.cc
@@ -255,17 +255,23 @@ class NaClProcessHost::ScopedChannelHandle {
   // Returns true if the given handle is closable automatically by this
   // class. This function is just a helper for validation.
   static bool IsSupportedHandle(const IPC::ChannelHandle& handle) {
-#if defined(OS_WIN)
+#if defined(OS_POSIX)
+    // Only ChannelMojo is supported.

[Mark Seaborn, 2016/10/12 00:57:24]

It looks like this comment should apply to Windows too.

[Sam McNally, 2016/10/12 03:15:32]

Done.

+    return handle.socket.fd == -1;
+#elif defined(OS_WIN)
     // On Windows, it is not supported to marshal the |pipe.handle|.
     // In our case, we wrap a transferred ChannelHandle (or one to be
     // transferred) via IPC, so we can assume |handle.pipe.handle| is NULL.
     return handle.pipe.handle == NULL;
 #else
     return true;
-#endif
+#endif  // defined(OS_POSIX)
   }
 
   void CloseIfNecessary() {
+    if (handle_.mojo_handle.is_valid())
+      handle_.mojo_handle.Close();
+
 #if defined(OS_POSIX)

[Mark Seaborn, 2016/10/12 00:57:24]

This block shouldn't be necessary if "Only ChannelMojo is supported" as noted
above.

[Sam McNally, 2016/10/12 03:15:32]

Done.

     if (handle_.socket.auto_close) {
       // Defer closing task to the ScopedFD.
@@ -1034,17 +1040,12 @@ bool NaClProcessHost::CreateChannelHandlePair(
   DCHECK(channel_handle1);
   DCHECK(channel_handle2);
 
-  int fd1 = -1;
-  int fd2 = -1;
-  if (!IPC::SocketPair(&fd1, &fd2)) {
-    return false;
-  }
+  IPC::ChannelHandle handle1;
+  IPC::ChannelHandle handle2;
+  IPC::Channel::GenerateMojoChannelHandlePair("NaCl", &handle1, &handle2);
+  channel_handle1->reset(handle1);
+  channel_handle2->reset(handle2);
 
-  IPC::ChannelHandle handle = IPC::Channel::GenerateVerifiedChannelID("nacl");
-  handle.socket = base::FileDescriptor(fd1, true);
-  channel_handle1->reset(handle);
-  handle.socket = base::FileDescriptor(fd2, true);
-  channel_handle2->reset(handle);
   return true;
 }
 #endif