Cleanup RemotePlatformLayer when disconnecting RemoteFrame.

Source/core/frame/RemoteFrame.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/frame/RemoteFrame.h"
 
 #include "bindings/core/v8/WindowProxyManager.h"
 #include "core/dom/RemoteSecurityContext.h"
 #include "core/frame/RemoteDOMWindow.h"
 #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 {
 
 inline RemoteFrame::RemoteFrame(RemoteFrameClient* client, FrameHost* host, FrameOwner* owner)
     : Frame(client, host, owner)
     , m_securityContext(RemoteSecurityContext::create())
     , m_domWindow(RemoteDOMWindow::create(*this))
     , m_windowProxyManager(WindowProxyManager::create(*this))
+    , m_remotePlatformLayer(nullptr)
 {
 }
 
 PassRefPtrWillBeRawPtr<RemoteFrame> RemoteFrame::create(RemoteFrameClient* client, FrameHost* host, FrameOwner* owner)
 {
     return adoptRefWillBeNoop(new RemoteFrame(client, host, owner));
 }
 
 RemoteFrame::~RemoteFrame()
 {
@@ skipping 39 matching lines @@
         return;
     m_windowProxyManager->clearForClose();
     Frame::detach();
 }
 
 RemoteSecurityContext* RemoteFrame::securityContext() const
 {
     return m_securityContext.get();
 }
 
+void RemoteFrame::disconnectOwnerElement()
+{
+    if (owner() && owner()->isLocal())

[dcheng, 2015/02/03 22:08:37]

Why do we do this work here instead of, say, RemoteFrame::detach()? Is there a
corresponding cleanup step for LocalFrames that we can mirror here?

Also, would it make more sense for this check to be something like:

if (m_remotePlatformLayer)
    setRemotePlatformLayer(nullptr);

[lfg, 2015/02/03 22:54:50]

It needs to run on both WebFrame::swap(), as well as detach(). It doesn't look
like there's any other place that would fit. (LocalFrame also have a
disconnectOwnerElement() override to do some cleanups).
This makes sense, changed.

[dcheng, 2015/02/04 00:02:23]

Can we add a comment to this effect? It's not immediately obvious to the reader
that that's the requirement for this logic belonging here. In addition, I think
there is a high chance that WebFrame::swap() will end up calling detach() on the
frames (but obviously that's still in flux).

+        setRemotePlatformLayer(nullptr);
+    Frame::disconnectOwnerElement();
+}
+
 void RemoteFrame::forwardInputEvent(Event* event)
 {
     remoteFrameClient()->forwardInputEvent(event);
 }
 
 void RemoteFrame::setView(PassRefPtrWillBeRawPtr<RemoteFrameView> view)
 {
     // Oilpan: as RemoteFrameView performs no finalization actions,
     // no explicit dispose() of it needed here. (cf. FrameView::dispose().)
     m_view = view;
 }
 
 void RemoteFrame::createView()
 {
     RefPtrWillBeRawPtr<RemoteFrameView> view = RemoteFrameView::create(this);
     setView(view);
 
     if (ownerRenderer()) {
         HTMLFrameOwnerElement* owner = deprecatedLocalOwner();
         ASSERT(owner);
         owner->setWidget(view);
     }
 }
 
 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