Start incremental marking in long idle notification for background tab

src/heap/heap.cc

 // Copyright 2012 the V8 project 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 "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 4938 matching lines @@
     if (FLAG_trace_idle_notification_verbose) {
       PrintF("[");
       heap_state.Print();
       PrintF("]");
     }
     PrintF("\n");
   }
 }
 
 
+void Heap::CheckAndNotifyBackgroundIdleNotification(double idle_time_in_ms,
+                                                    double now_ms) {
+  if (idle_time_in_ms >= GCIdleTimeHandler::kMinBackgroundIdleTime) {
+    MemoryReducer::Event event;
+    event.type = MemoryReducer::kBackgroundIdleNotification;
+    event.time_ms = now_ms;
+    event.can_start_incremental_gc = incremental_marking()->IsStopped() &&
+                                     incremental_marking()->CanBeActivated();
+    memory_reducer_.NotifyBackgroundIdleNotification(event);
+  }
+}
+
+
 double Heap::MonotonicallyIncreasingTimeInMs() {
   return V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() *
          static_cast<double>(base::Time::kMillisecondsPerSecond);
 }
 
 
 bool Heap::IdleNotification(int idle_time_in_ms) {
   return IdleNotification(
       V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() +
       (static_cast<double>(idle_time_in_ms) /
        static_cast<double>(base::Time::kMillisecondsPerSecond)));
 }
 
 
 bool Heap::IdleNotification(double deadline_in_seconds) {
   CHECK(HasBeenSetUp());
   double deadline_in_ms =
       deadline_in_seconds *
       static_cast<double>(base::Time::kMillisecondsPerSecond);
   HistogramTimerScope idle_notification_scope(
       isolate_->counters()->gc_idle_notification());
   double start_ms = MonotonicallyIncreasingTimeInMs();
   double idle_time_in_ms = deadline_in_ms - start_ms;
 
+  CheckAndNotifyBackgroundIdleNotification(idle_time_in_ms, start_ms);
+
   tracer()->SampleAllocation(start_ms, NewSpaceAllocationCounter(),
                              OldGenerationAllocationCounter());
 
   GCIdleTimeHandler::HeapState heap_state = ComputeHeapState();
 
   GCIdleTimeAction action =
       gc_idle_time_handler_.Compute(idle_time_in_ms, heap_state);
 
   bool result = PerformIdleTimeAction(action, heap_state, deadline_in_ms);
 
@@ skipping 1884 matching lines @@
     *object_type = "CODE_TYPE";                                                \
     *object_sub_type = "CODE_AGE/" #name;                                      \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 }  // namespace internal
 }  // namespace v8