[heap, debugger] Introduce out-of-memory listener for debugger.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 316c5772a04d5bd941fb8bf863769a7580e38a43..ec2a470abb8268897290511a34ea60ec5be12c57 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -95,6 +95,8 @@ Heap::Heap()
       survived_last_scavenge_(0),
       always_allocate_scope_count_(0),
       memory_pressure_level_(MemoryPressureLevel::kNone),
+      out_of_memory_callback_(nullptr),
+      out_of_memory_callback_data_(nullptr),
       contexts_disposed_(0),
       number_of_disposed_maps_(0),
       global_ic_age_(0),
@@ -867,6 +869,9 @@ void Heap::CollectAllAvailableGarbage(GarbageCollectionReason gc_reason) {
   // Note: as weak callbacks can execute arbitrary code, we cannot
   // hope that eventually there will be no weak callbacks invocations.
   // Therefore stop recollecting after several attempts.
+  if (gc_reason == GarbageCollectionReason::kLastResort) {
+    InvokeOutOfMemoryCallback();
+  }
   RuntimeCallTimerScope(isolate(), &RuntimeCallStats::GC_AllAvailableGarbage);
   if (isolate()->concurrent_recompilation_enabled()) {
     // The optimizing compiler may be unnecessarily holding on to memory.
@@ -4534,6 +4539,18 @@ void Heap::MemoryPressureNotification(MemoryPressureLevel level,
   }
 }
 
+void Heap::SetOutOfMemoryCallback(v8::debug::OutOfMemoryCallback callback,
+                                  void* data) {
+  out_of_memory_callback_ = callback;
+  out_of_memory_callback_data_ = data;
+}
+
+void Heap::InvokeOutOfMemoryCallback() {
+  if (out_of_memory_callback_) {
+    out_of_memory_callback_(out_of_memory_callback_data_);
+  }
+}
+
 void Heap::CollectCodeStatistics() {
   CodeStatistics::ResetCodeAndMetadataStatistics(isolate());
   // We do not look for code in new space, or map space.  If code