[scheduler] Delay budget-based throttling for 10s after backgrounded.

third_party/WebKit/Source/platform/scheduler/renderer/web_view_scheduler_impl.h

Index: third_party/WebKit/Source/platform/scheduler/renderer/web_view_scheduler_impl.h
diff --git a/third_party/WebKit/Source/platform/scheduler/renderer/web_view_scheduler_impl.h b/third_party/WebKit/Source/platform/scheduler/renderer/web_view_scheduler_impl.h
index efa5c44c16567a02a30e76f426849c5978c4e938..1d9b47578dfb7e415df08941952f43c6d9536960 100644
--- a/third_party/WebKit/Source/platform/scheduler/renderer/web_view_scheduler_impl.h
+++ b/third_party/WebKit/Source/platform/scheduler/renderer/web_view_scheduler_impl.h
@@ -79,6 +79,12 @@ class BLINK_PLATFORM_EXPORT WebViewSchedulerImpl : public WebViewScheduler {
   static const char* VirtualTimePolicyToString(
       VirtualTimePolicy virtual_time_policy);
 
+  // Depending on page visibility, either turns budget throttling off, or
+  // schedules a call to enable it after a grace period.
+  void UpdateBackgroundBudgetThrottlingState();
+
+  void EnableBackgroundBudgetThrottling();
+
   std::set<WebFrameSchedulerImpl*> frame_schedulers_;
   std::set<unsigned long> pending_loads_;
   WebScheduler::InterventionReporter* intervention_reporter_;  // Not owned.
@@ -94,6 +100,7 @@ class BLINK_PLATFORM_EXPORT WebViewSchedulerImpl : public WebViewScheduler {
   bool reported_background_throttling_since_navigation_;
   TaskQueueThrottler::TimeBudgetPool*
       background_time_budget_pool_;  // Not owned.
+  CancelableClosureHolder delayed_background_budget_throttling_enabler_;
   WebViewScheduler::WebViewSchedulerSettings* settings_;  // Not owned.
 
   DISALLOW_COPY_AND_ASSIGN(WebViewSchedulerImpl);