diff -r 000000000000 -r 6474c204b198 dom/activities/src/Activity.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/activities/src/Activity.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,90 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "Activity.h"
+
+#include "nsContentUtils.h"
+#include "nsDOMClassInfo.h"
+#include "nsIConsoleService.h"
+#include "nsIDocShell.h"
+#include "nsIDocument.h"
+
+using namespace mozilla::dom;
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(Activity)
+NS_INTERFACE_MAP_END_INHERITING(DOMRequest)
+
+NS_IMPL_ADDREF_INHERITED(Activity, DOMRequest)
+NS_IMPL_RELEASE_INHERITED(Activity, DOMRequest)
+
+NS_IMPL_CYCLE_COLLECTION_INHERITED(Activity, DOMRequest,
+                                   mProxy)
+
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(Activity, DOMRequest)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
+/* virtual */ JSObject*
+Activity::WrapObject(JSContext* aCx)
+{
+  return MozActivityBinding::Wrap(aCx, this);
+}
+
+nsresult
+Activity::Initialize(nsPIDOMWindow* aWindow,
+                     JSContext* aCx,
+                     const ActivityOptions& aOptions)
+{
+  MOZ_ASSERT(aWindow);
+
+  nsCOMPtr<nsIDocument> document = aWindow->GetExtantDoc();
+
+  bool isActive;
+  aWindow->GetDocShell()->GetIsActive(&isActive);
+
+  if (!isActive &&
+      !nsContentUtils::IsChromeDoc(document)) {
+    nsCOMPtr<nsIDOMRequestService> rs =
+      do_GetService("@mozilla.org/dom/dom-request-service;1");
+    rs->FireErrorAsync(static_cast<DOMRequest*>(this),
+                       NS_LITERAL_STRING("NotUserInput"));
+
+    nsCOMPtr<nsIConsoleService> console(
+      do_GetService("@mozilla.org/consoleservice;1"));
+    NS_ENSURE_TRUE(console, NS_OK);
+
+    nsString message =
+      NS_LITERAL_STRING("Can only start activity from user input or chrome code");
+    console->LogStringMessage(message.get());
+
+    return NS_OK;
+  }
+
+  // Instantiate a JS proxy that will do the child <-> parent communication
+  // with the JS implementation of the backend.
+  nsresult rv;
+  mProxy = do_CreateInstance("@mozilla.org/dom/activities/proxy;1", &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  JS::Rooted<JS::Value> optionsValue(aCx);
+  if (!aOptions.ToObject(aCx, &optionsValue)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mProxy->StartActivity(static_cast<nsIDOMDOMRequest*>(this), optionsValue, aWindow);
+  return NS_OK;
+}
+
+Activity::~Activity()
+{
+  if (mProxy) {
+    mProxy->Cleanup();
+  }
+}
+
+Activity::Activity(nsPIDOMWindow* aWindow)
+  : DOMRequest(aWindow)
+{
+  MOZ_ASSERT(IsDOMBinding());
+}
+