First step in enabling creating tabs without an Activity on Android.

content/browser/service_worker/service_worker_version.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/service_worker/service_worker_version.h"
 
 #include "base/command_line.h"
 #include "base/memory/ref_counted.h"
 #include "base/stl_util.h"
 #include "base/strings/string16.h"
@@ skipping 192 matching lines @@
                                        render_frame_id));
     Observe(nullptr);
     base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
   }
 
   const WindowOpenedCallback callback_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowOpenedObserver);
 };
 
+void DidOpenWindowOnUI(
+    const WindowOpenedCallback& callback, WebContents* web_contents) {
+  DCHECK(web_contents);
+
+  new WindowOpenedObserver(web_contents, callback);
+}
+
 void OpenWindowOnUI(
     const GURL& url,
     const GURL& script_url,
     int process_id,
     const scoped_refptr<ServiceWorkerContextWrapper>& context_wrapper,
     const WindowOpenedCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   BrowserContext* browser_context = context_wrapper->storage_partition()
       ? context_wrapper->storage_partition()->browser_context()
@@ skipping 11 matching lines @@
                                        MSG_ROUTING_NONE));
     return;
   }
 
   OpenURLParams params(url,
                        Referrer(script_url, blink::WebReferrerPolicyDefault),
                        NEW_FOREGROUND_TAB,
                        ui::PAGE_TRANSITION_AUTO_TOPLEVEL,
                        false);
 
-  WebContents* web_contents =
-      GetContentClient()->browser()->OpenURL(browser_context, params);
-  DCHECK(web_contents);
-
-  new WindowOpenedObserver(web_contents, callback);
+  GetContentClient()->browser()->OpenURL(
+      browser_context, params,
+      base::Bind(&DidOpenWindowOnUI, callback));
 }
 
 void KillEmbeddedWorkerProcess(int process_id, ResultCode code) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   RenderProcessHost* render_process_host =
       RenderProcessHost::FromID(process_id);
   if (render_process_host->GetHandle() != base::kNullProcessHandle)
     render_process_host->ReceivedBadMessage();
 }
@@ skipping 1091 matching lines @@
     int request_id) {
   callbacks->Remove(request_id);
   if (is_doomed_) {
     // The stop should be already scheduled, but try to stop immediately, in
     // order to release worker resources soon.
     StopWorkerIfIdle();
   }
 }
 
 }  // namespace content