Fix up that no render SVG shape when change clip-path to visible after hidden.

third_party/WebKit/Source/core/layout/svg/LayoutSVGResourceContainer.cpp

Index: third_party/WebKit/Source/core/layout/svg/LayoutSVGResourceContainer.cpp
diff --git a/third_party/WebKit/Source/core/layout/svg/LayoutSVGResourceContainer.cpp b/third_party/WebKit/Source/core/layout/svg/LayoutSVGResourceContainer.cpp
index 6bfb64b4d40e99dad8fb6f6fbf6be7633253c801..a79b0ef368db447b2cc6859ef204190305a64d2f 100644
--- a/third_party/WebKit/Source/core/layout/svg/LayoutSVGResourceContainer.cpp
+++ b/third_party/WebKit/Source/core/layout/svg/LayoutSVGResourceContainer.cpp
@@ -85,6 +85,28 @@ void LayoutSVGResourceContainer::styleDidChange(StyleDifference diff,
                                                 const ComputedStyle* oldStyle) {
   LayoutSVGHiddenContainer::styleDidChange(diff, oldStyle);
 
+  for (auto* client : m_clients) {
+    // Check whether delete the old resource or not for client that is NoChange.
+    // If ResourceContainer is visible, client is visible, width and height
+    // are '0', the old cache should be removed and set pending resource.
+    LayoutRect boundingBox = client->visualRect();
+    if (style()->visibility() == EVisibility::Visible &&

[fs, 2017/01/05 17:01:47]

I think this may be starting to approach the right track, but not quite there
yet. The 'visibility' on the LayoutSVGResourceContainer itself (<clipPath>,
<mask> and <pattern> I think are the relevant ones here) does not actually have
any influence on the actual "content". So, I'd expect the invalidation to take
place through the children of the LayoutSVGResourceContainer (probably via
SVGResourceCache::clientStyleChanged?)

+        client->style()->visibility() == EVisibility::Visible &&
+        !boundingBox.width() && !boundingBox.height())
+    {
+      SVGResources* resources =
+          SVGResourcesCache::cachedResourcesForLayoutObject(client);
+      if (resources) {
+        // Remove the old resource.

[fs, 2017/01/05 17:01:47]

This looks too heavy-handed, if you wanted to invalidate clients,
removeAllClientsFromCache would probably be better. (If you want to be
selective, removeClientFromCache.) You should also not be
unregistering/re-registering the resource.

+        resources->resourceDestroyed(this);
+        Element* clientElement = toElement(client->node());
+         svgExtensionsFromElement(clientElement)
+          .addPendingResource(m_id, clientElement);
+        m_registered = false;
+      }
+    }
+  }
+
   if (!m_registered) {
     m_registered = true;
     registerResource();