Resume a backgrounded renderer that was purged and suspended

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 2d679e3236f31b2710423d7f5d4cf2d2d85d1a73..dbee07e5bcdf0af6894c1893fca4886b13085f6a 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -993,6 +993,8 @@ bool RenderProcessHostImpl::Init() {
 
   is_initialized_ = true;
   init_time_ = base::TimeTicks::Now();
+  last_purged_and_suspended_time_ = base::TimeTicks::FromInternalValue(0);
+  last_resumed_time_ = last_purged_and_suspended_time_;

[hajimehoshi, 2016/09/30 11:22:46]

Is this updated when the tab is foregrounded and resumed?

[tasak, 2016/10/03 05:44:16]

No. This is only updated when the tab is backgrounded and resumed.
When the tab is foregrounded, the last active time is updated.

   return true;
 }
 
@@ -1428,6 +1430,21 @@ bool RenderProcessHostImpl::IsWorkerRefCountDisabled() {
 
 void RenderProcessHostImpl::PurgeAndSuspend() {
   Send(new ChildProcessMsg_PurgeAndSuspend());
+  last_purged_and_suspended_time_ = base::TimeTicks::Now();
+}
+
+void RenderProcessHostImpl::Resume() {
+  Send(new ChildProcessMsg_Resume());
+  last_resumed_time_ = base::TimeTicks::Now();
+}
+
+const base::TimeTicks& RenderProcessHostImpl::GetLastPurgedAndSuspendedTime()
+    const {
+  return last_purged_and_suspended_time_;
+}
+
+const base::TimeTicks& RenderProcessHostImpl::GetLastResumedTime() const {
+  return last_resumed_time_;
 }
 
 mojom::RouteProvider* RenderProcessHostImpl::GetRemoteRouteProvider() {