Even without --trace-gc dump the last few GC messages on OOM

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 74f4ac1412bebf28f023dbca26da68fc70eced9a..60f7749e79f9e4b3957f9cf1241547135775701f 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -144,6 +144,8 @@ Heap::Heap()
       new_space_allocation_counter_(0),
       gcs_since_last_deopt_(0),
       allocation_sites_scratchpad_length_(0),
+      ring_buffer_full_(false),
+      ring_buffer_end_(0),
       promotion_queue_(this),
       configured_(false),
       external_string_table_(this),
@@ -5260,6 +5262,30 @@ bool Heap::ConfigureHeap(int max_semi_space_size, int max_old_space_size,
 }
 
 
+void Heap::AddToRingBuffer(const char* string) {
+  size_t first_part =
+      Min(strlen(string), kTraceRingBufferSize - ring_buffer_end_);
+  memcpy(trace_ring_buffer_ + ring_buffer_end_, string, first_part);
+  ring_buffer_end_ += first_part;
+  if (first_part < strlen(string)) {
+    ring_buffer_full_ = true;
+    size_t second_part = strlen(string) - first_part;
+    memcpy(trace_ring_buffer_, string + first_part, second_part);
+    ring_buffer_end_ = second_part;
+  }
+}
+
+
+void Heap::GetFromRingBuffer(char* buffer) {
+  size_t copied = 0;
+  if (ring_buffer_full_) {
+    copied = kTraceRingBufferSize - ring_buffer_end_;
+    memcpy(buffer, trace_ring_buffer_ + ring_buffer_end_, copied);
+  }
+  memcpy(buffer + copied, trace_ring_buffer_, ring_buffer_end_);
+}
+
+
 bool Heap::ConfigureHeapDefault() { return ConfigureHeap(0, 0, 0, 0); }
 
 
@@ -5292,6 +5318,8 @@ void Heap::RecordStats(HeapStats* stats, bool take_snapshot) {
       stats->size_per_type[type] += obj->Size();
     }
   }
+  if (stats->last_few_messages != NULL)
+    GetFromRingBuffer(stats->last_few_messages);
 }