[cleanup] Several small clean-ups in our concurrent tests

Clean-ups:
 * Remove the detaching of persistent handles from the LocalHeap if the
main thread will not get the handles from the background thread.
 * Remove unused isolate member.
 * Make members private/protected as needed.

Bug: v8:7790
Change-Id: I23bf4a41124bd04d4a848edfa1ef8f9e8e77182c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2463234Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70442}

test/cctest/test-concurrent-descriptor-array.cc

@@ -56,11 +56,9 @@ class ConcurrentSearchThread final : public v8::base::Thread {
     }
 
     CHECK_EQ(handles_.size(), kNumHandles * 2);
-
-    CHECK(!ph_);
-    ph_ = local_heap.DetachPersistentHandles();
   }
 
+ private:
   Heap* heap_;
   std::vector<Handle<JSObject>> handles_;
   std::unique_ptr<PersistentHandles> ph_;

test/cctest/test-concurrent-prototype.cc

@@ -55,11 +55,9 @@ class ConcurrentSearchThread final : public v8::base::Thread {
     }
 
     CHECK_EQ(handles_.size(), kNumHandles * 2);
-
-    CHECK(!ph_);
-    ph_ = local_heap.DetachPersistentHandles();
   }
 
+ private:
   Heap* heap_;
   std::vector<Handle<JSObject>> handles_;
   std::unique_ptr<PersistentHandles> ph_;

test/cctest/test-concurrent-script-context-table.cc

@@ -28,7 +28,6 @@ class ScriptContextTableAccessUsedThread final : public v8::base::Thread {
       Handle<ScriptContextTable> script_context_table)
       : v8::base::Thread(
             base::Thread::Options("ScriptContextTableAccessUsedThread")),
-        isolate_(isolate),
         heap_(heap),
         sema_started_(sema_started),
         ph_(std::move(ph)),
@@ -44,12 +43,9 @@ class ScriptContextTableAccessUsedThread final : public v8::base::Thread {
       Context context = script_context_table_->get_context(i);
       CHECK(context.IsScriptContext());
     }
-
-    CHECK(!ph_);
-    ph_ = local_heap.DetachPersistentHandles();
   }
 
-  Isolate* isolate_;
+ private:
   Heap* heap_;
   base::Semaphore* sema_started_;
   std::unique_ptr<PersistentHandles> ph_;
@@ -64,7 +60,6 @@ class AccessScriptContextTableThread final : public v8::base::Thread {
                                  Handle<NativeContext> native_context)
       : v8::base::Thread(
             base::Thread::Options("AccessScriptContextTableThread")),
-        isolate_(isolate),
         heap_(heap),
         sema_started_(sema_started),
         ph_(std::move(ph)),
@@ -87,12 +82,9 @@ class AccessScriptContextTableThread final : public v8::base::Thread {
                               &local_heap);
       CHECK(!context.is_null());
     }
-
-    CHECK(!ph_);
-    ph_ = local_heap.DetachPersistentHandles();
   }
 
-  Isolate* isolate_;
+ private:
   Heap* heap_;
   base::Semaphore* sema_started_;
   std::unique_ptr<PersistentHandles> ph_;

test/cctest/test-concurrent-transition-array.cc

@@ -41,11 +41,10 @@ class ConcurrentSearchThread : public v8::base::Thread {
     CHECK_EQ(TransitionsAccessor(CcTest::i_isolate(), map_, true)
                  .SearchTransition(*name_, kData, NONE),
              result_map_ ? **result_map_ : Map());
-
-    CHECK(!ph_);
-    ph_ = local_heap.DetachPersistentHandles();
   }
 
+  // protected instead of private due to having a subclass.
+ protected:
   Heap* heap_;
   base::Semaphore* background_thread_started_;
   std::unique_ptr<PersistentHandles> ph_;

test/cctest/test-persistent-handles.cc

@@ -65,6 +65,12 @@ class PersistentHandlesThread final : public v8::base::Thread {
     ph_ = local_heap.DetachPersistentHandles();
   }
 
+  std::unique_ptr<PersistentHandles> DetachPersistentHandles() {
+    CHECK(ph_);
+    return std::move(ph_);
+  }
+
+ private:
   Heap* heap_;
   std::vector<Handle<HeapNumber>> handles_;
   std::unique_ptr<PersistentHandles> ph_;
@@ -105,7 +111,7 @@ TEST(CreatePersistentHandles) {
   thread->Join();
 
   // get persistent handles back to main thread
-  ph = std::move(thread->ph_);
+  ph = thread->DetachPersistentHandles();
   ph->NewHandle(number);
 }