Render delegated renderer frames using the Qt scene graph.

This provides a stub implementation that renders quads and RenderPasses
using QSGNodes in QQuickWebEngineView.
The BackingStore code path is still supported when the delegated renderer
switch is not enabled. To use the new rendering, pass the following switches:
--enable-delegated-renderer --enable-threaded-compositing

This uses debug, plain color textures until we can fetch tiles and
textures from the ResourceProvider across OpenGL context boundaries.

Change-Id: I33ea0738dc5a326ef79c1435f75c044c42e8551f
Reviewed-by: Zeno Albisser <zeno.albisser@digia.com>

1 files changed, 25 insertions, 3 deletions

diff --git a/lib/quick/render_widget_host_view_qt_delegate_quick.cpp b/lib/quick/render_widget_host_view_qt_delegate_quick.cpp
index 6f8243690..b77503f2c 100644
--- a/lib/quick/render_widget_host_view_qt_delegate_quick.cpp
+++ b/lib/quick/render_widget_host_view_qt_delegate_quick.cpp
@@ -41,6 +41,30 @@
 
 #include "render_widget_host_view_qt_delegate_quick.h"
 
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 2, 0))
+RenderWidgetHostViewQtDelegateQuick::RenderWidgetHostViewQtDelegateQuick(QQuickItem *parent)
+    : RenderWidgetHostViewQtDelegateQuickBase<QQuickItem>(parent)
+{
+    setFlag(ItemHasContents);
+}
+
+WId RenderWidgetHostViewQtDelegateQuick::nativeWindowIdForCompositor() const
+{
+    return QQuickItem::window()->winId();
+}
+
+void RenderWidgetHostViewQtDelegateQuick::update(const QRect&)
+{
+    QQuickItem::update();
+}
+
+QSGNode *RenderWidgetHostViewQtDelegateQuick::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
+{
+    return RenderWidgetHostViewQtDelegate::updatePaintNode(oldNode, QQuickItem::window());
+}
+#endif // QT_VERSION
+
+
 RenderWidgetHostViewQtDelegateQuickPainted::RenderWidgetHostViewQtDelegateQuickPainted(QQuickItem *parent)
     : RenderWidgetHostViewQtDelegateQuickBase<QQuickPaintedItem>(parent)
 {
@@ -48,9 +72,7 @@ RenderWidgetHostViewQtDelegateQuickPainted::RenderWidgetHostViewQtDelegateQuickP
 
 WId RenderWidgetHostViewQtDelegateQuickPainted::nativeWindowIdForCompositor() const
 {
-    // Only used to enable accelerated compositing by the compositor
-    // directly on our native window, which we want to eventually do
-    // through the delegated renderer instead.
+    // This causes a failure of the compositor initialization which ends up disabling it completely.
     return 0;
 }