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

shell/child_process_host.h

Index: shell/child_process_host.h
diff --git a/shell/child_process_host.h b/shell/child_process_host.h
index 7ae2d9bf127ffd559fe86200c84860042a5a5083..3a1928b0ac1b963d83f60ed74f815a641486564b 100644
--- a/shell/child_process_host.h
+++ b/shell/child_process_host.h
@@ -40,7 +40,7 @@ class ChildProcessHost {
   // 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);
 
   // 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