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..f66745705b5333b41d5555fe96a218e292cb665c 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 ShouldAnticipateHighPriorityWork() = 0;

[alex clarke (OOO till 29th), 2015/01/26 17:16:00]

Functionality seems fine, but I'm not sure about the name. Maybe
HighPriorityWorkAnticipated?

[jdduke (slow), 2015/01/26 20:14:48]

Yeah, changed to |IsHighPriorityWorkAnticipated| to make it clear it's a query
not a notification (as we can't simply make the method const).

+
   // 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 |ShouldAnticipateHighPriorityWork|,
+  // restricted to the case where real work is pending.
   // Must be called from the main thread.
   virtual bool ShouldYieldForHighPriorityWork() = 0;