[Experiment] purge-and-suspend

third_party/WebKit/Source/core/frame/FrameView.cpp

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index 687b58d8451b0789bb81f5d439dc29cfbdc80004..a2df7775f48a3aa13eebbc6a15add681eacf4b9e 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -4292,4 +4292,19 @@ bool FrameView::canThrottleRendering() const
     return m_subtreeThrottled || (m_hiddenForThrottling && m_crossOriginForThrottling);
 }
 
+void FrameView::purgeMemory()
+{
+    LayoutViewItem viewItem = layoutViewItem();
+    DCHECK(!viewItem.isNull());
+
+    PaintLayer* layer = viewItem.layer();
+    DCHECK(layer);
+    if (!layer->hasCompositedLayerMapping())
+        return;
+    GraphicsLayer* rootGraphicsLayer = layer->compositedLayerMapping()->mainGraphicsLayer();
+    if (!rootGraphicsLayer->drawsContent())
+        return;
+    rootGraphicsLayer->getPaintController().invalidateAll();

[esprehn, 2016/08/05 23:00:58]

This is only the main graphics layer, what about all of the other ones? Are we
sure this does the right thing?

[tasak, 2016/08/08 04:47:36]

I see. I would like to traverse all children and to invoke their
paintController's "invalidateAll()".

+}
+
 } // namespace blink