Remove promotion backup case and report OOM instead.

src/heap/mark-compact.cc

Index: src/heap/mark-compact.cc
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index 77d084266264fbd78f56bc16115818a92b223ff4..1c5299fb6021b67fbcfd16e41bf81c6010660faa 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -1861,26 +1861,27 @@ int MarkCompactCollector::DiscoverAndEvacuateBlackObjectsOnPage(
       current_cell >>= 1;
 
       // TODO(hpayer): Refactor EvacuateObject and call this function instead.
-      if (heap()->ShouldBePromoted(object->address(), size) &&
-          TryPromoteObject(object, size)) {
-        continue;
-      }
-
-      AllocationResult allocation = new_space->AllocateRaw(size);
-      if (allocation.IsRetry()) {
-        if (!new_space->AddFreshPage()) {
-          // Shouldn't happen. We are sweeping linearly, and to-space
-          // has the same number of pages as from-space, so there is
-          // always room.
-          UNREACHABLE();
+      if (heap()->ShouldBePromoted(object->address(), size)) {
+        if (!TryPromoteObject(object, size)) {
+          V8::FatalProcessOutOfMemory("Full GC promotion failed");
         }
-        allocation = new_space->AllocateRaw(size);
-        DCHECK(!allocation.IsRetry());
-      }
-      Object* target = allocation.ToObjectChecked();
+      } else {
+        AllocationResult allocation = new_space->AllocateRaw(size);
+        if (allocation.IsRetry()) {
+          if (!new_space->AddFreshPage()) {
+            // Shouldn't happen. We are sweeping linearly, and to-space
+            // has the same number of pages as from-space, so there is
+            // always room.
+            UNREACHABLE();
+          }
+          allocation = new_space->AllocateRaw(size);
+          DCHECK(!allocation.IsRetry());
+        }
+        Object* target = allocation.ToObjectChecked();
 
-      MigrateObject(HeapObject::cast(target), object, size, NEW_SPACE);
-      heap()->IncrementSemiSpaceCopiedObjectSize(size);
+        MigrateObject(HeapObject::cast(target), object, size, NEW_SPACE);
+        heap()->IncrementSemiSpaceCopiedObjectSize(size);
+      }
     }
     *cells = 0;
   }