Cleanup RemotePlatformLayer when disconnecting RemoteFrame.

Source/core/frame/RemoteFrame.cpp

Index: Source/core/frame/RemoteFrame.cpp
diff --git a/Source/core/frame/RemoteFrame.cpp b/Source/core/frame/RemoteFrame.cpp
index cde4b2c8623e530e1db70262c23eed7c597734f4..909c47d45595e38338cbd3be967d22e98b651118 100644
--- a/Source/core/frame/RemoteFrame.cpp
+++ b/Source/core/frame/RemoteFrame.cpp
@@ -10,7 +10,11 @@
 #include "core/frame/RemoteFrameClient.h"
 #include "core/frame/RemoteFrameView.h"
 #include "core/html/HTMLFrameOwnerElement.h"
+#include "core/rendering/RenderLayer.h"
+#include "core/rendering/RenderPart.h"
+#include "platform/graphics/GraphicsLayer.h"
 #include "platform/weborigin/SecurityPolicy.h"
+#include "public/platform/WebLayer.h"
 
 namespace blink {
 
@@ -70,6 +74,13 @@ RemoteSecurityContext* RemoteFrame::securityContext() const
     return m_securityContext.get();
 }
 
+void RemoteFrame::disconnectOwnerElement()
+{
+    if (owner() && owner()->isLocal())
+        setRemotePlatformLayer(nullptr);
+    Frame::disconnectOwnerElement();
+}
+
 void RemoteFrame::forwardInputEvent(Event* event)
 {
     remoteFrameClient()->forwardInputEvent(event);
@@ -99,4 +110,18 @@ RemoteFrameClient* RemoteFrame::remoteFrameClient() const
     return static_cast<RemoteFrameClient*>(client());
 }
 
+void RemoteFrame::setRemotePlatformLayer(WebLayer* layer)
+{
+    if (m_remotePlatformLayer)
+        GraphicsLayer::unregisterContentsLayer(m_remotePlatformLayer);
+    m_remotePlatformLayer = layer;
+    if (m_remotePlatformLayer)
+        GraphicsLayer::registerContentsLayer(layer);
+
+    ASSERT(owner());
+    toHTMLFrameOwnerElement(owner())->setNeedsCompositingUpdate();
+    if (RenderPart* renderer = ownerRenderer())
+        renderer->layer()->updateSelfPaintingLayer();
+}
+
 } // namespace blink