Document-relative overlays disappear after doing page-cache navigations

https://bugs.webkit.org/show_bug.cgi?id=135669
<rdar://problem/17929171>

Reviewed by Simon Fraser.

* rendering/RenderLayerCompositor.cpp:
(WebCore::RenderLayerCompositor::rootLayerAttachmentChanged):
When navigating from one page to another, the document-relative overlay
layer is moved from the layer tree of the RenderLayerCompositor of the
first RenderView to the layer tree of the RenderLayerCompositor of the
new RenderView, upon layer tree construction.
When going "back" via a page cache navigation, we don't rebuild the
layer tree, and just assume that it is in a valid state.
However, the document-relative overlay layer was *moved*, and as such,
needs to be moved back. To do this, reattach the document-relative
overlay layer whenever the root layer attachment of a RenderLayerCompositor
changes, which will happen in the right order when going back to a cached page.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@172179 268f45cc-cd09-0410-ab3c-d52691b4dbfc

diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index e356bbe3eb148ab2503fb2739bb833e9bbcd4e03..77094242e0511e2908ddef4b3169c4d54debbffa 100644 (file)
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,24 @@
+2014-08-06  Tim Horton  <timothy_horton@apple.com>
+
+        Document-relative overlays disappear after doing page-cache navigations
+        https://bugs.webkit.org/show_bug.cgi?id=135669
+        <rdar://problem/17929171>
+
+        Reviewed by Simon Fraser.
+
+        * rendering/RenderLayerCompositor.cpp:
+        (WebCore::RenderLayerCompositor::rootLayerAttachmentChanged):
+        When navigating from one page to another, the document-relative overlay
+        layer is moved from the layer tree of the RenderLayerCompositor of the
+        first RenderView to the layer tree of the RenderLayerCompositor of the
+        new RenderView, upon layer tree construction.
+        When going "back" via a page cache navigation, we don't rebuild the
+        layer tree, and just assume that it is in a valid state.
+        However, the document-relative overlay layer was *moved*, and as such,
+        needs to be moved back. To do this, reattach the document-relative
+        overlay layer whenever the root layer attachment of a RenderLayerCompositor
+        changes, which will happen in the right order when going back to a cached page.
+
 2014-08-06  Filip Pizlo  <fpizlo@apple.com>
 
         Merge r171389, r171495, r171508, r171510, r171605, r171606, r171611, r171614, r171763 from ftlopt.

diff --git a/Source/WebCore/rendering/RenderLayerCompositor.cpp b/Source/WebCore/rendering/RenderLayerCompositor.cpp
index 1a29773975dbe787d6bbc8ba0e5e7ef071a12fa3..6aeba1e3d8c20edb96c251eb53482cb036ecca16 100644 (file)
--- a/Source/WebCore/rendering/RenderLayerCompositor.cpp
+++ b/Source/WebCore/rendering/RenderLayerCompositor.cpp
@@ -3423,6 +3423,20 @@ void RenderLayerCompositor::rootLayerAttachmentChanged()
     RenderLayer* layer = m_renderView.layer();
     if (RenderLayerBacking* backing = layer ? layer->backing() : 0)
         backing->updateDrawsContent();
+
+    // The document-relative page overlay layer (which is pinned to the main frame's layer tree)
+    // is moved between different RenderLayerCompositors' layer trees, and needs to be
+    // reattached whenever we swap in a new RenderLayerCompositor.
+    if (m_rootLayerAttachment == RootLayerUnattached)
+        return;
+
+    Frame& frame = m_renderView.frameView().frame();
+    Page* page = frame.page();
+    if (!page)
+        return;
+
+    if (GraphicsLayer* overlayLayer = page->chrome().client().documentOverlayLayerForFrame(frame))
+        m_rootContentLayer->addChild(overlayLayer);
 }
 
 // IFrames are special, because we hook compositing layers together across iframe boundaries