Allow custom security descriptors when creating named pipes on Windows.

mojo/edk/embedder/named_platform_handle_utils.h

Index: mojo/edk/embedder/named_platform_handle_utils.h
diff --git a/mojo/edk/embedder/named_platform_handle_utils.h b/mojo/edk/embedder/named_platform_handle_utils.h
index 6b856bb52f03c3ff0ac8c30468a9724704810045..f13e1765fabb6d3d417436a397a0dbcceb5f30e8 100644
--- a/mojo/edk/embedder/named_platform_handle_utils.h
+++ b/mojo/edk/embedder/named_platform_handle_utils.h
@@ -9,21 +9,37 @@
 #include "mojo/edk/embedder/scoped_platform_handle.h"
 #include "mojo/edk/system/system_impl_export.h"
 
+#if defined(OS_WIN)
+#include "base/strings/string16.h"
+#endif
+
 namespace mojo {
 namespace edk {
 
 struct NamedPlatformHandle;
 
+struct CreateServerHandleOptions {
+#if defined(OS_WIN)
+  // If true, creating a server handle will fail if another pipe with the same
+  // name exists.
+  bool enforce_uniqueness = true;
+
+  // If non-empty, a security descriptor to use when creating the pipe. If
+  // empty, a default security descriptor will be used. See
+  // kDefaultSecurityDescriptor in named_platform_handle_utils_win.cc.
+  base::string16 security_descriptor;
+#endif
+};
+
 // Creates a client platform handle from |handle|. This may block until |handle|
 // is ready to receive connections.
 MOJO_SYSTEM_IMPL_EXPORT ScopedPlatformHandle
 CreateClientHandle(const NamedPlatformHandle& handle);
 
-// Creates a server platform handle from |handle|. On Windows, if
-// |enforce_uniqueness| is true, this will fail if another pipe with the same
-// name exists. On other platforms, |enforce_uniqueness| must be false.
+// Creates a server platform handle from |handle|.
 MOJO_SYSTEM_IMPL_EXPORT ScopedPlatformHandle
-CreateServerHandle(const NamedPlatformHandle& handle, bool enforce_uniqueness);
+CreateServerHandle(const NamedPlatformHandle& handle,
+                   const CreateServerHandleOptions& options = {});
 
 }  // namespace edk
 }  // namespace mojo