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 23dfa4720749c85b546f9aea1b7b5a338b3e01de..049c3599cbccd680edb0af07baa2e0917c9c2905 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 +556,19 @@ WebVector<WebIconURL> WebFrameImpl::iconURLs(int iconTypesMask) const
     return WebVector<WebIconURL>();
 }
 
+void WebFrameImpl::setRemoteWebLayer(WebLayer* webLayer)
+{
+    if (!frame())
+        return;
+
+    if (frame()->remotePlatformLayer())
+        GraphicsLayer::unregisterContentsLayer(frame()->remotePlatformLayer());
+    if (webLayer)
+        GraphicsLayer::registerContentsLayer(webLayer);
+    frame()->setRemotePlatformLayer(webLayer);
+    frame()->ownerElement()->setNeedsStyleRecalc(WebCore::SubtreeStyleChange, WebCore::StyleChangeFromRenderer);
+}
+
 WebSize WebFrameImpl::scrollOffset() const
 {
     FrameView* view = frameView();