Experimental 'purging and suspending' backgrounded tabs behind the flag

content/child/child_thread_impl.cc

 // Copyright (c) 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.
 
 #include "content/child/child_thread_impl.h"
 
 #include <signal.h>
 #include <string>
 #include <utility>
 
@@ skipping 619 matching lines @@
                         OnSetIPCLoggingEnabled)
 #endif
     IPC_MESSAGE_HANDLER(ChildProcessMsg_SetProfilerStatus,
                         OnSetProfilerStatus)
     IPC_MESSAGE_HANDLER(ChildProcessMsg_GetChildProfilerData,
                         OnGetChildProfilerData)
     IPC_MESSAGE_HANDLER(ChildProcessMsg_ProfilingPhaseCompleted,
                         OnProfilingPhaseCompleted)
     IPC_MESSAGE_HANDLER(ChildProcessMsg_SetProcessBackgrounded,
                         OnProcessBackgrounded)
+    IPC_MESSAGE_HANDLER(ChildProcessMsg_PurgeAndSuspend,
+                        OnProcessPurgeAndSuspend)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   if (handled)
     return true;
 
   if (msg.routing_id() == MSG_ROUTING_CONTROL)
     return OnControlMessageReceived(msg);
 
   return router_.OnMessageReceived(msg);
 }
 
 bool ChildThreadImpl::OnControlMessageReceived(const IPC::Message& msg) {
   return false;
 }
 
 void ChildThreadImpl::OnProcessBackgrounded(bool backgrounded) {
   // Set timer slack to maximum on main thread when in background.
   base::TimerSlack timer_slack = base::TIMER_SLACK_NONE;
   if (backgrounded)
     timer_slack = base::TIMER_SLACK_MAXIMUM;
   base::MessageLoop::current()->SetTimerSlack(timer_slack);
 }
 
+void ChildThreadImpl::OnProcessPurgeAndSuspend() {
+}
+
 void ChildThreadImpl::OnShutdown() {
   base::MessageLoop::current()->QuitWhenIdle();
 }
 
 #if defined(IPC_MESSAGE_LOG_ENABLED)
 void ChildThreadImpl::OnSetIPCLoggingEnabled(bool enable) {
   if (enable)
     IPC::Logging::GetInstance()->Enable();
   else
     IPC::Logging::GetInstance()->Disable();
@@ skipping 47 matching lines @@
 void ChildThreadImpl::EnsureConnected() {
   VLOG(0) << "ChildThreadImpl::EnsureConnected()";
   base::Process::Current().Terminate(0, false);
 }
 
 bool ChildThreadImpl::IsInBrowserProcess() const {
   return static_cast<bool>(browser_process_io_runner_);
 }
 
 }  // namespace content