Very basic Android browser-side compositing support.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 61d98d8faab7f8eaa2baecf2311112c8b073bb36..c5529ed8afd7192b2ebdacfefe4c6518764f1964 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -1440,6 +1440,16 @@ void WebContentsImpl::RequestMediaAccessPermission(
     callback.Run(content::MediaStreamDevices());
 }
 
+void WebContentsImpl::AttachLayer(WebKit::WebLayer& layer) {
+  if (delegate_)
+    delegate_->AttachLayer(this, layer);
+}
+
+void WebContentsImpl::RemoveLayer(WebKit::WebLayer& layer) {
+  if (delegate_)
+    delegate_->RemoveLayer(this, layer);
+}
+
 void WebContentsImpl::UpdatePreferredSize(const gfx::Size& pref_size) {
   preferred_size_ = pref_size;
   if (delegate_)