Experimental 'purging and suspending' backgrounded tabs behind the flag

components/scheduler/renderer/renderer_scheduler.h

Index: components/scheduler/renderer/renderer_scheduler.h
diff --git a/components/scheduler/renderer/renderer_scheduler.h b/components/scheduler/renderer/renderer_scheduler.h
index 7bf5c7fe9e928370ffe302f3cfc7fcd2e32ca161..3d0ac1d0499da8933a3cfbabe29631230128fde7 100644
--- a/components/scheduler/renderer/renderer_scheduler.h
+++ b/components/scheduler/renderer/renderer_scheduler.h
@@ -128,6 +128,10 @@ class SCHEDULER_EXPORT RendererScheduler : public ChildScheduler {
   // Must be called on the main thread.
   virtual void OnRendererForegrounded() = 0;
 
+  // Tells the scheduler that the render process should be suspended as long as
+  // the renderer process is backgrounded.
+  virtual void SuspendRendererWhenBackgrounded() = 0;
+
   // Tells the scheduler that a navigation task is pending. While any navigation
   // tasks are pending, the scheduler will ensure that loading tasks are not
   // blocked even if they are expensive. Must be called on the main thread.