Use conservative heap growing factor 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 91 matching lines @@
       dump_allocations_hash_countdown_(FLAG_dump_allocations_digest_at_alloc),
       ms_count_(0),
       gc_count_(0),
       remembered_unmapped_pages_index_(0),
       unflattened_strings_length_(0),
 #ifdef DEBUG
       allocation_timeout_(0),
 #endif  // DEBUG
       old_generation_allocation_limit_(initial_old_generation_size_),
       old_gen_exhausted_(false),
+      optimize_for_memory_usage_(false),
       inline_allocation_disabled_(false),
       store_buffer_rebuilder_(store_buffer()),
       hidden_string_(NULL),
       gc_safe_size_of_old_object_(NULL),
       total_regexp_code_generated_(0),
       tracer_(this),
       high_survival_rate_period_length_(0),
       promoted_objects_size_(0),
       promotion_ratio_(0),
       semi_space_copied_object_size_(0),
@@ skipping 4777 matching lines @@
 
 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);
+    optimize_for_memory_usage_ = true;
+  } else {
+    optimize_for_memory_usage_ = false;
   }
 }
 
 
 double Heap::MonotonicallyIncreasingTimeInMs() {
   return V8::GetCurrentPlatform()->MonotonicallyIncreasingTime() *
          static_cast<double>(base::Time::kMillisecondsPerSecond);
 }
 
 
@@ skipping 675 matching lines @@
   }
 
   // We set the old generation growing factor to 2 to grow the heap slower on
   // memory-constrained devices.
   if (max_old_generation_size_ <= kMaxOldSpaceSizeMediumMemoryDevice ||
       FLAG_optimize_for_size) {
     factor = Min(factor, kMaxHeapGrowingFactorMemoryConstrained);
   }
 
   if (freed_global_handles >= kFreedGlobalHandlesThreshold ||
-      memory_reducer_.ShouldGrowHeapSlowly()) {
+      memory_reducer_.ShouldGrowHeapSlowly() || optimize_for_memory_usage_) {
     factor = Min(factor, kConservativeHeapGrowingFactor);
   }
 
   if (FLAG_stress_compaction ||
       mark_compact_collector()->reduce_memory_footprint_) {
     factor = kMinHeapGrowingFactor;
   }
 
   old_generation_allocation_limit_ =
       CalculateOldGenerationAllocationLimit(factor, old_gen_size);
@@ skipping 1243 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