Don't support threaded GL on chromium (virtual box GL)

Change-Id: I84f89450e3fce1cbbafd19dbf4509b1911e06b19
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>

src/plugins/platforms/xcb/qglxintegration.cpp

@@ -408,6 +408,38 @@ bool QGLXContext::isValid() const
     return m_context != 0;
 }
 
+bool QGLXContext::m_queriedDummyContext = false;
+bool QGLXContext::m_supportsThreading = true;
+
+void QGLXContext::queryDummyContext()
+{
+    if (m_queriedDummyContext)
+        return;
+    m_queriedDummyContext = true;
+
+    static bool skip = qEnvironmentVariableIsSet("QT_OPENGL_NO_SANITY_CHECK");
+    if (skip)
+        return;
+
+    QOffscreenSurface surface;
+    surface.create();
+    QOpenGLContext context;
+    context.create();
+    context.makeCurrent(&surface);
+
+    const char *renderer = (const char *) glGetString(GL_RENDERER);
+    if (QByteArray(renderer).contains("Chromium"))
+        m_supportsThreading = false;
+    else
+        m_supportsThreading = true;
+}
+
+bool QGLXContext::supportsThreading()
+{
+    if (!m_queriedDummyContext)
+        queryDummyContext();
+    return m_supportsThreading;
+}
 
 QGLXPbuffer::QGLXPbuffer(QOffscreenSurface *offscreenSurface)
     : QPlatformOffscreenSurface(offscreenSurface)

src/plugins/platforms/xcb/qglxintegration.h

@@ -72,12 +72,18 @@ public:
 
     GLXContext glxContext() const { return m_context; }
 
+    static bool supportsThreading();
+    static void queryDummyContext();
+
 private:
     QXcbScreen *m_screen;
     GLXContext m_context;
     GLXContext m_shareContext;
     QSurfaceFormat m_format;
     bool m_isPBufferCurrent;
+
+    static bool m_queriedDummyContext;
+    static bool m_supportsThreading;
 };
 
 

src/plugins/platforms/xcb/qxcbintegration.cpp

@@ -278,7 +278,7 @@ bool QXcbIntegration::hasCapability(QPlatformIntegration::Capability cap) const
 #else
     case OpenGL: return false;
 #endif
-    case ThreadedOpenGL: return m_connections.at(0)->supportsThreadedRendering();
+    case ThreadedOpenGL: return m_connections.at(0)->supportsThreadedRendering() && QGLXContext::supportsThreading();
     case WindowMasks: return true;
     case MultipleWindows: return true;
     case ForeignWindows: return true;