Reland "Throttle resource message requests during user interaction"

content/renderer/scheduler/renderer_scheduler.h

Index: content/renderer/scheduler/renderer_scheduler.h
diff --git a/content/renderer/scheduler/renderer_scheduler.h b/content/renderer/scheduler/renderer_scheduler.h
index f8a206081ad753cb016a492f65bd10c85d15865e..e1b5c578d244b2e3f2569f13369d3cc740e0c06b 100644
--- a/content/renderer/scheduler/renderer_scheduler.h
+++ b/content/renderer/scheduler/renderer_scheduler.h
@@ -53,8 +53,16 @@ class CONTENT_EXPORT RendererScheduler {
   // a fling). Called by the compositor (impl) thread.
   virtual void DidAnimateForInputOnCompositorThread() = 0;
 
+  // Returns true if the scheduler has reason to believe that high priority work
+  // may soon arrive on the main thread, e.g., if gesture events were observed
+  // recently.
+  // Must be called from the main thread.
+  virtual bool IsHighPriorityWorkAnticipated() = 0;
+
   // Returns true if there is high priority work pending on the main thread
-  // and the caller should yield to let the scheduler service that work.
+  // and the caller should yield to let the scheduler service that work. Note
+  // that this is a stricter condition than |IsHighPriorityWorkAnticipated|,
+  // restricted to the case where real work is pending.
   // Must be called from the main thread.
   virtual bool ShouldYieldForHighPriorityWork() = 0;