cppgc: Various trivial fixes

- Document internal namespace
- Various trivial fixes

Bug: chromium:1056170
Change-Id: If527d491a37d7ccd0aa4ff829ccc5dc06c02da38
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2246569
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68349}

include/cppgc/heap.h

@@ -20,6 +20,11 @@ namespace cppgc {
 
 class AllocationHandle;
 
+/**
+ * Implementation details of cppgc. Those details are considered internal and
+ * may change at any point in time without notice. Users should never rely on
+ * the contents of this namespace.
+ */
 namespace internal {
 class Heap;
 }  // namespace internal

src/heap/cppgc/heap-base.h

@@ -61,6 +61,9 @@ class V8_EXPORT_PRIVATE HeapBase {
   HeapBase(std::shared_ptr<cppgc::Platform> platform, size_t custom_spaces);
   virtual ~HeapBase();
 
+  HeapBase(const HeapBase&) = delete;
+  HeapBase& operator=(const HeapBase&) = delete;
+
   RawHeap& raw_heap() { return raw_heap_; }
   const RawHeap& raw_heap() const { return raw_heap_; }
 

src/heap/cppgc/marker.cc

@@ -33,9 +33,6 @@ void ExitIncrementalMarkingIfNeeded(Marker::MarkingConfig config) {
   }
 }
 
-}  // namespace
-
-namespace {
 template <typename Worklist, typename Callback>
 bool DrainWorklistWithDeadline(v8::base::TimeTicks deadline, Worklist* worklist,
                                Callback callback, int task_id) {

src/heap/cppgc/marking-visitor.cc

@@ -76,7 +76,7 @@ void MarkingVisitor::VisitWeakRoot(const void* object, TraceDescriptor desc,
     // construction, then it should be reachable from the stack.
     return;
   }
-  // Since weak roots arev only traced at the end of marking, we can execute
+  // Since weak roots are only traced at the end of marking, we can execute
   // the callback instead of registering it.
   weak_callback(LivenessBrokerFactory::Create(), weak_root);
 }