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

shell/child_process_host.h

 // 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.
 
 #ifndef SHELL_CHILD_PROCESS_HOST_H_
 #define SHELL_CHILD_PROCESS_HOST_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 22 matching lines @@
   // (see |DidStart()|).
   virtual ~ChildProcessHost();
 
   // |Start()|s the child process; calls |DidStart()| (on the thread on which
   // |Start()| was called) when the child has been started (or failed to start).
   // After calling |Start()|, this object must not be destroyed until
   // |DidStart()| has been called.
   // TODO(vtl): Consider using weak pointers and removing this requirement.
   // TODO(vtl): This should probably take a callback instead.
   // TODO(vtl): Consider merging this with |StartApp()|.
-  void Start();
+  void Start(bool require_32_bit);

[Petr Hosek, 2015/09/14 19:13:52]

What if Mojo is built as 32-bit? Wouldn't it be better to define an enum for the
target architecture (unless there is already one) and use it here?

[Sean Klein, 2015/09/15 18:37:50]

An enum may eventually be useful, but at the moment, the only functionality is a
request to use a pre-built 32-bit shell for the nonsfi content handler. This
value should be independent of the built architecture -- though it might be
"unnecessary" if the rest of mojo is built as 32 bit, it will still work.

 
   // Waits for the child process to terminate, and returns its exit code.
   // Note: If |Start()| has been called, this must not be called until the
   // callback has been called.
   int Join();
 
   // Methods relayed to the |ChildController|. These methods may be only be
   // called after |Start()|, but may be called immediately (without waiting for
   // |DidStart()|).
 
@@ skipping 29 matching lines @@
   ChildController::StartAppCallback on_app_complete_;
 
   base::Process child_process_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildProcessHost);
 };
 
 }  // namespace shell
 
 #endif  // SHELL_CHILD_PROCESS_HOST_H_