Experimental 'purging and suspending' backgrounded tabs behind the flag

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright 2012 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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 1110 matching lines @@
 }
 
 void RenderProcessHostImpl::DecrementWorkerRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK_GT(worker_ref_count_, 0);
   --worker_ref_count_;
   if (worker_ref_count_ == 0)
     Cleanup();
 }
 
+void RenderProcessHostImpl::PurgeAndSuspend() {
+  Send(new ChildProcessMsg_PurgeAndSuspend());
+}
+
 void RenderProcessHostImpl::AddRoute(int32_t routing_id,
                                      IPC::Listener* listener) {
   CHECK(!listeners_.Lookup(routing_id)) << "Found Routing ID Conflict: "
                                         << routing_id;
   listeners_.AddWithID(listener, routing_id);
 }
 
 void RenderProcessHostImpl::RemoveRoute(int32_t routing_id) {
   DCHECK(listeners_.Lookup(routing_id) != NULL);
   listeners_.Remove(routing_id);
@@ skipping 1621 matching lines @@
 
     // Skip widgets in other processes.
     if (rvh->GetProcess()->GetID() != GetID())
       continue;
 
     rvh->OnWebkitPreferencesChanged();
   }
 }
 
 }  // namespace content