Attach a WebLayer to a frame element for out-of-process iframes.

Source/web/WebFrameImpl.cpp

Index: Source/web/WebFrameImpl.cpp
diff --git a/Source/web/WebFrameImpl.cpp b/Source/web/WebFrameImpl.cpp
index 10805151cae5733c820f851c3f9890237a31ca69..f4c00cf58b151548ebbfa3609523dbd8746e412f 100644
--- a/Source/web/WebFrameImpl.cpp
+++ b/Source/web/WebFrameImpl.cpp
@@ -188,6 +188,7 @@
 #include "public/platform/WebFileSystem.h"
 #include "public/platform/WebFloatPoint.h"
 #include "public/platform/WebFloatRect.h"
+#include "public/platform/WebLayer.h"
 #include "public/platform/WebPoint.h"
 #include "public/platform/WebRect.h"
 #include "public/platform/WebSize.h"
@@ -555,6 +556,18 @@ WebVector<WebIconURL> WebFrameImpl::iconURLs(int iconTypesMask) const
     return WebVector<WebIconURL>();
 }
 
+void WebFrameImpl::setWebLayer(WebLayer* webLayer)
+{
+    if (frame() && frame()->ownerElement()) {
+        if (frame()->ownerElement()->platformLayer())
+            GraphicsLayer::unregisterContentsLayer(frame()->ownerElement()->platformLayer());
+        if (webLayer)
+            GraphicsLayer::registerContentsLayer(webLayer);
+        frame()->ownerElement()->setPlatformLayer(webLayer);
+        frame()->ownerElement()->setNeedsStyleRecalc(WebCore::SubtreeStyleChange, WebCore::StyleChangeFromRenderer);
+    }
+}
+
 WebSize WebFrameImpl::scrollOffset() const
 {
     FrameView* view = frameView();