Add GLContextHelper class for EGL context creation.

Shared EGL contexts should always be created on the same
thread, as otherwise context creation might fail.
We use a GLContextHelper singleton that is initialized
on startup and creates the contexts when requested
through a BlockingQueuedConnection.

There is a pretty and a correct solution for this problem.
This is the pretty one. It is based on the assumption
that Chromium decides to use the same or a similar enough
configuration for the EGLContext as Qt previously did.
But we prefer pretty over correct as the correct solution
would potentially impose a layering violation.

This is enabled for all embedded linux devices.

Change-Id: I910cc90d0f87fd6d1fe0a475b17ba56cd8c503f6
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/src/core/gl_context_qt.h b/src/core/gl_context_qt.h
new file mode 100644
index 000000000..efe8958be
--- /dev/null
+++ b/src/core/gl_context_qt.h
@@ -0,0 +1,69 @@
+/****************************************************************************
+**
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
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+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
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+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef GL_GL_CONTEXT_QT_H_
+#define GL_GL_CONTEXT_QT_H_
+
+#include <QObject>
+
+QT_BEGIN_NAMESPACE
+
+namespace gfx {
+class GLContext;
+class GLSurface;
+}
+
+class GLContextHelper : public QObject {
+    Q_OBJECT
+public:
+    static void initialize();
+    static bool initializeContext(gfx::GLContext* context, gfx::GLSurface* surface);
+
+private:
+    Q_INVOKABLE bool initializeContextOnBrowserThread(gfx::GLContext* context, gfx::GLSurface* surface);
+
+    static GLContextHelper* contextHelper;
+};
+
+QT_END_NAMESPACE
+
+#endif
+