Mark JSArrayBuffer::SetupAllocatingData with WARN_UNUSED_RESULT.

test/cctest/heap/test-page-promotion.cc

 // Copyright 2016 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/factory.h"
 #include "src/heap/array-buffer-tracker.h"
 #include "src/heap/spaces-inl.h"
 #include "src/isolate.h"
 // FIXME(mstarzinger, marja): This is weird, but required because of the missing
 // (disallowed) include: src/factory.h -> src/objects-inl.h
@@ skipping 97 matching lines @@
     v8::Isolate::Scope isolate_scope(isolate);
     v8::HandleScope handle_scope(isolate);
     v8::Context::New(isolate)->Enter();
     Heap* heap = i_isolate->heap();
 
     // Fill the current page which potentially contains the age mark.
     heap::FillCurrentPage(heap->new_space());
     // Allocate a buffer we would like to check against.
     Handle<JSArrayBuffer> buffer =
         i_isolate->factory()->NewJSArrayBuffer(SharedFlag::kNotShared);
-    JSArrayBuffer::SetupAllocatingData(buffer, i_isolate, 100);
+    CHECK(JSArrayBuffer::SetupAllocatingData(buffer, i_isolate, 100));
     std::vector<Handle<FixedArray>> handles;
     // Simulate a full space, filling the interesting page with live objects.
     heap::SimulateFullSpace(heap->new_space(), &handles);
     CHECK_GT(handles.size(), 0u);
     // Last object in handles should definitely be on the last page which does
     // not contain the age mark.
     Handle<FixedArray> first_object = handles.front();
     Page* to_be_promoted_page = Page::FromAddress(first_object->address());
     CHECK(to_be_promoted_page->Contains(first_object->address()));
     CHECK(to_be_promoted_page->Contains(buffer->address()));
@@ skipping 36 matching lines @@
     heap->CollectGarbage(NEW_SPACE, i::GarbageCollectionReason::kTesting);
     heap->new_space()->Shrink();
     heap->memory_allocator()->unmapper()->WaitUntilCompleted();
     heap->mark_compact_collector()->sweeper().StartSweeperTasks();
     heap->mark_compact_collector()->EnsureSweepingCompleted();
   }
 }
 
 }  // namespace internal
 }  // namespace v8