Add missing doc file for cocoa native context

Change-Id: I11938311f648ba63bd9bee2e518c7525871cd0a3
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>

src/platformheaders/nativecontexts/qcocoanativecontext.qdoc

@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Free Documentation License Usage
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of
+** this file.  Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: http://www.gnu.org/copyleft/fdl.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+  \class QCocoaNativeContext
+  \inmodule QtPlatformHeaders
+  \since 5.4
+
+  \brief A class encapsulating a Cocoa NSOpenGLContext.
+
+  \note There is no binary compatibility guarantee for this class, meaning
+  that an application using it is only guaranteed to work with the Qt version it was
+  developed against.
+
+  \sa QOpenGLContext::setNativeHandle(), QOpenGLContext::nativeHandle()
+ */
+
+/*!
+  \fn NSOpenGLContext *QCocoaNativeContext::context() const
+
+  \return the context.
+ */
+
+/*!
+  \fn QCocoaNativeContext::QCocoaNativeContext()
+
+  Construct a new instance with no handles.
+ */
+
+/*!
+  \fn QCocoaNativeContext::QCocoaNativeContext(NSOpenGLContext *ctx)
+
+  Constructs a new instance with the provided \a ctx handle.
+ */