3 files changed, 12 insertions, 2 deletions
diff --git a/src/core/delegated_frame_node.cpp b/src/core/delegated_frame_node.cpp
index d704bf234..2cfcd4afe 100644
--- a/src/core/delegated_frame_node.cpp
+++ b/src/core/delegated_frame_node.cpp
@@ -332,6 +332,13 @@ void DelegatedFrameNode::commit(DelegatedFrameNodeData* data, cc::ReturnedResour
     if (!frameData)
         return;
 
+    // DelegatedFrameNode is a transform node only for the purpose of
+    // countering the scale of devicePixel-scaled tiles when rendering them
+    // to the final surface.
+    QMatrix4x4 matrix;
+    matrix.scale(1 / m_data->frameDevicePixelRatio, 1 / m_data->frameDevicePixelRatio);
+    setMatrix(matrix);
+
     // Keep the old texture lists around to find the ones we can re-use.
     QList<QSharedPointer<RenderPassTexture> > oldRenderPassTextures;
     m_renderPassTextures.swap(oldRenderPassTextures);
@@ -368,7 +375,7 @@ void DelegatedFrameNode::commit(DelegatedFrameNodeData* data, cc::ReturnedResour
                 rpTexture = QSharedPointer<RenderPassTexture>(new RenderPassTexture(pass->id, sgrc));
             }
             m_renderPassTextures.append(rpTexture);
-            rpTexture->setDevicePixelRatio(m_window->devicePixelRatio());
+            rpTexture->setDevicePixelRatio(m_data->frameDevicePixelRatio);
             rpTexture->setRect(toQt(pass->output_rect));
             rpTexture->setFormat(pass->has_transparent_background ? GL_RGBA : GL_RGB);
             renderPassParent = rpTexture->rootNode();
diff --git a/src/core/delegated_frame_node.h b/src/core/delegated_frame_node.h
index 842f53011..71a3e1d25 100644
--- a/src/core/delegated_frame_node.h
+++ b/src/core/delegated_frame_node.h
@@ -65,11 +65,13 @@ class RenderPassTexture;
 // and render pass information.
 class DelegatedFrameNodeData : public QSharedData {
 public:
+    DelegatedFrameNodeData() : frameDevicePixelRatio(1) { }
     QHash<unsigned, QSharedPointer<MailboxTexture> > mailboxTextures;
     scoped_ptr<cc::DelegatedFrameData> frameData;
+    qreal frameDevicePixelRatio;
 };
 
-class DelegatedFrameNode : public QSGNode {
+class DelegatedFrameNode : public QSGTransformNode {
 public:
     DelegatedFrameNode(QQuickWindow *window);
     ~DelegatedFrameNode();
diff --git a/src/core/render_widget_host_view_qt.cpp b/src/core/render_widget_host_view_qt.cpp
index d9822769c..dc2e1c155 100644
--- a/src/core/render_widget_host_view_qt.cpp
+++ b/src/core/render_widget_host_view_qt.cpp
@@ -599,6 +599,7 @@ void RenderWidgetHostViewQt::OnSwapCompositorFrame(uint32 output_surface_id, sco
     Q_ASSERT(frame->delegated_frame_data);
     Q_ASSERT(!m_frameNodeData->frameData || m_frameNodeData->frameData->resource_list.empty());
     m_frameNodeData->frameData = frame->delegated_frame_data.Pass();
+    m_frameNodeData->frameDevicePixelRatio = frame->metadata.device_scale_factor;
     m_delegate->update();
 }