Wait for sweeper threads when expansion of old generation fails.

src/spaces.cc

Index: src/spaces.cc
diff --git a/src/spaces.cc b/src/spaces.cc
index 22233d9b3c2d011aa1ff8d59740cd97228689dc1..72a0222ba454d6c77d7bd8c714095bcee72100c8 100644
--- a/src/spaces.cc
+++ b/src/spaces.cc
@@ -2595,6 +2595,16 @@ HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) {
   // collection.
   if (!heap()->always_allocate() &&
       heap()->OldGenerationAllocationLimitReached()) {
+    // If sweeper threads are active, wait for them at that point.
+     if (collector->IsConcurrentSweepingInProgress()) {
+       collector->WaitUntilSweepingCompleted();
+
+       // After waiting for the sweeper threads, there may be new free-list
+       // entries.
+       HeapObject* object = free_list_.Allocate(size_in_bytes);
+       if (object != NULL) return object;
+     }
+
     return NULL;
   }
 
@@ -2604,16 +2614,6 @@ HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) {
     return free_list_.Allocate(size_in_bytes);
   }
 
-  // If sweeper threads are active, wait for them at that point.
-  if (collector->IsConcurrentSweepingInProgress()) {
-    collector->WaitUntilSweepingCompleted();
-
-    // After waiting for the sweeper threads, there may be new free-list
-    // entries.
-    HeapObject* object = free_list_.Allocate(size_in_bytes);
-    if (object != NULL) return object;
-  }
-
   // Finally, fail.
   return NULL;
 }