Move content's shell connections to the IO thread

content/public/common/connection_filter.h

Index: content/public/common/connection_filter.h
diff --git a/content/public/common/connection_filter.h b/content/public/common/connection_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..be8da3fb00839193de913d3c11f2bf9b8c5347d2
--- /dev/null
+++ b/content/public/common/connection_filter.h
@@ -0,0 +1,40 @@
+// Copyright 2016 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 CONTENT_PUBLIC_COMMON_CONNECTION_FILTER_H_
+#define CONTENT_PUBLIC_COMMON_CONNECTION_FILTER_H_
+
+#include "content/common/content_export.h"
+
+namespace shell {
+class Connection;
+class Connector;
+}
+
+namespace content {
+
+// A ConnectionFilter may be used to conditionally expose interfaces on inbound
+// connections accepted by MojoShellConnection. ConnectionFilters are used
+// exclusively on the IO thread. See MojoShellConnection::AddConnectionFilter
+// for details.
+class CONTENT_EXPORT ConnectionFilter {
+ public:
+  virtual ~ConnectionFilter() {}
+
+  // Called for every new connection accepted. Implementations may add
+  // interfaces to |connection|, in which case they should return |true|.
+  // |connector| is a corresponding outgoing Connector that may be used by any
+  // interfaces added to the connection. Note that references to |connector|
+  // must not be retained, but an owned copy may be obtained by calling
+  // |connector->Clone()|.
+  //
+  // If a ConnectionFilter is not interested in an incoming connection, it
+  // should return |false|.
+  virtual bool OnConnect(shell::Connection* connection,
+                         shell::Connector* connector) = 0;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_COMMON_CONNECTION_FILTER_H_