Create a new action triggered when a BeginMainFrame is not expected before vsync

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/scheduler/renderer/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 434 matching lines @@
     return;
 
   MainThreadOnly().begin_frame_not_expected_soon = true;
   idle_helper_.EnableLongIdlePeriod();
   {
     base::AutoLock lock(any_thread_lock_);
     AnyThread().begin_main_frame_on_critical_path = false;
   }
 }
 
+void RendererSchedulerImpl::DoShortIdleWork(const cc::BeginFrameArgs& args) {
+  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
+               "RendererSchedulerImpl::DoShortIdleWork");
+  helper_.CheckOnValidThread();
+  if (helper_.IsShutdown())
+    return;
+
+  base::TimeTicks now(helper_.scheduler_tqm_delegate()->NowTicks());
+  base::TimeTicks estimated_next_frame_begin = args.frame_time + args.interval;
+
+  if (now < estimated_next_frame_begin) {
+    // TODO(rmcilroy): Consider reducing the idle period based on the runtime of
+    // the next pending delayed tasks (as currently done in for long idle times)
+    idle_helper_.StartIdlePeriod(
+        IdleHelper::IdlePeriodState::IN_SHORT_IDLE_PERIOD, now,
+        estimated_next_frame_begin);
+  }
+}
+
 void RendererSchedulerImpl::SetAllRenderWidgetsHidden(bool hidden) {
   TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                "RendererSchedulerImpl::SetAllRenderWidgetsHidden", "hidden",
                hidden);
 
   helper_.CheckOnValidThread();
 
   if (helper_.IsShutdown() || MainThreadOnly().renderer_hidden == hidden)
     return;
 
@@ skipping 1450 matching lines @@
     case TimeDomainType::VIRTUAL:
       return "virtual";
     default:
       NOTREACHED();
       return nullptr;
   }
 }
 
 }  // namespace scheduler
 }  // namespace blink