Enabling 64-bit mojo shell to launch 32-bit child to handle nonsfi content.

shell/child_process_host.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "shell/child_process_host.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 24 matching lines @@
 };
 
 ChildProcessHost::ChildProcessHost(Context* context)
     : context_(context), channel_info_(nullptr) {
 }
 
 ChildProcessHost::~ChildProcessHost() {
   DCHECK(!child_process_.IsValid());
 }
 
-void ChildProcessHost::Start() {
+void ChildProcessHost::Start(bool require_32_bit) {
   DCHECK(!child_process_.IsValid());
 
   scoped_ptr<LaunchData> launch_data(new LaunchData());
   launch_data->child_path = context_->mojo_shell_child_path();
+  if (require_32_bit)
+    launch_data->child_path =
+        context_->mojo_shell_child_path().InsertBeforeExtensionASCII("_32");

[Mark Seaborn, 2015/09/15 19:42:58]

It seems like this should be inside an "#if defined(ARCH_CPU_X86_64)".  Adding
this suffix is only wanted when mojo_shell is built for x86-64.

[Sean Klein, 2015/09/15 21:35:40]

Using ARCH_CPU_64_BITS to work with ARM too.

 
   // TODO(vtl): Add something for |slave_info|.
   // TODO(vtl): The "unretained this" is wrong (see also below).
   mojo::ScopedMessagePipeHandle handle(mojo::embedder::ConnectToSlave(
       nullptr, launch_data->platform_channel_pair.PassServerHandle(),
       base::Bind(&ChildProcessHost::DidConnectToSlave, base::Unretained(this)),
       base::MessageLoop::current()->message_loop_proxy(),
       &launch_data->child_connection_id, &channel_info_));
   // TODO(vtl): We should destroy the channel on destruction (using
   // |channel_info_|, but only after the callback has been called.
@@ skipping 87 matching lines @@
     on_app_complete_.reset();
     on_app_complete.Run(result);
   }
 }
 
 void ChildProcessHost::OnConnectionError() {
   AppCompleted(MOJO_RESULT_UNKNOWN);
 }
 
 }  // namespace shell