app_shell: Add experimental shellPrivate extension API

extensions/browser/api/shell_private/shell_private_api.h

Index: extensions/browser/api/shell_private/shell_private_api.h
diff --git a/extensions/browser/api/shell_private/shell_private_api.h b/extensions/browser/api/shell_private/shell_private_api.h
new file mode 100644
index 0000000000000000000000000000000000000000..660540762cf4ac769c3b8cf4b8fcfdb5d53b5d0b
--- /dev/null
+++ b/extensions/browser/api/shell_private/shell_private_api.h
@@ -0,0 +1,32 @@
+// 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 EXTENSIONS_BROWSER_API_SHELL_PRIVATE_SHELL_PRIVATE_API_H_
+#define EXTENSIONS_BROWSER_API_SHELL_PRIVATE_SHELL_PRIVATE_API_H_
+
+#include "base/macros.h"
+#include "extensions/browser/extension_function.h"
+
+namespace extensions {
+
+// Synchronously prints "hello" to the console.
+class ShellPrivatePrintHelloFunction : public UIThreadExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("shellPrivate.printHello", UNKNOWN);
+
+  ShellPrivatePrintHelloFunction();
+
+ protected:
+  virtual ~ShellPrivatePrintHelloFunction();
+
+  // ExtensionFunction:
+  virtual ResponseAction Run() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ShellPrivatePrintHelloFunction);
+};
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_API_SHELL_PRIVATE_SHELL_PRIVATE_API_H_