cppgc: Fix -Wshadow warning in cppgc and related unittests

Bug: v8:12244,v8:12245
Change-Id: Ic2d324fa5a3bde18b4fdbe7d64e44c7fc9ccd4ea
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3181534Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77042}

src/heap/cppgc/heap-object-header.h

@@ -120,14 +120,14 @@ class HeapObjectHeader {
 
   static constexpr size_t DecodeSize(uint16_t encoded) {
     // Essentially, gets optimized to << 1.
-    using SizeField = MarkBitField::Next<size_t, 15>;
-    return SizeField::decode(encoded) * kAllocationGranularity;
+    using SizeFieldImpl = MarkBitField::Next<size_t, 15>;
+    return SizeFieldImpl::decode(encoded) * kAllocationGranularity;
   }
 
   static constexpr uint16_t EncodeSize(size_t size) {
     // Essentially, gets optimized to >> 1.
-    using SizeField = MarkBitField::Next<size_t, 15>;
-    return SizeField::encode(size / kAllocationGranularity);
+    using SizeFieldImpl = MarkBitField::Next<size_t, 15>;
+    return SizeFieldImpl::encode(size / kAllocationGranularity);
   }
 
   V8_EXPORT_PRIVATE void CheckApiConstants();

src/heap/cppgc/marker.cc

@@ -214,7 +214,7 @@ void MarkerBase::StartMarking() {
 
   is_marking_ = true;
   if (EnterIncrementalMarkingIfNeeded(config_, heap())) {
-    StatsCollector::EnabledScope stats_scope(
+    StatsCollector::EnabledScope inner_stats_scope(
         heap().stats_collector(), StatsCollector::kMarkIncrementalStart);
 
     // Performing incremental or concurrent marking.
@@ -510,7 +510,7 @@ bool MarkerBase::ProcessWorklistsWithDeadline(
     }
 
     {
-      StatsCollector::EnabledScope stats_scope(
+      StatsCollector::EnabledScope inner_stats_scope(
           heap().stats_collector(), StatsCollector::kMarkProcessEphemerons);
       if (!DrainWorklistWithBytesAndTimeDeadline(
               mutator_marking_state_, marked_bytes_deadline, time_deadline,

src/heap/cppgc/sweeper.cc

@@ -817,7 +817,7 @@ class Sweeper::SweeperImpl final {
       MutatorThreadSweeper sweeper(&space_states_, platform_,
                                    config_.free_memory_handling);
       {
-        StatsCollector::EnabledScope stats_scope(
+        StatsCollector::EnabledScope inner_stats_scope(
             stats_collector_, internal_scope_id, "deltaInSeconds",
             deadline_in_seconds - platform_->MonotonicallyIncreasingTime());
 

test/unittests/heap/unified-heap-unittest.cc

@@ -147,7 +147,7 @@ class Unreferenced : public cppgc::GarbageCollected<Unreferenced> {
 }  // namespace
 
 TEST_F(UnifiedHeapTest, FreeUnreferencedDuringNoGcScope) {
-  v8::HandleScope scope(v8_isolate());
+  v8::HandleScope handle_scope(v8_isolate());
   v8::Local<v8::Context> context = v8::Context::New(v8_isolate());
   v8::Context::Scope context_scope(context);
   auto* unreferenced = cppgc::MakeGarbageCollected<Unreferenced>(
@@ -156,7 +156,7 @@ TEST_F(UnifiedHeapTest, FreeUnreferencedDuringNoGcScope) {
   // Force safepoint to force flushing of cached allocated/freed sizes in cppgc.
   cpp_heap().stats_collector()->NotifySafePointForTesting();
   {
-    cppgc::subtle::NoGarbageCollectionScope scope(cpp_heap());
+    cppgc::subtle::NoGarbageCollectionScope no_gc_scope(cpp_heap());
     cppgc::internal::FreeUnreferencedObject(cpp_heap(), unreferenced);
     // Force safepoint to make sure allocated size decrease due to freeing
     // unreferenced object is reported to CppHeap. Due to
@@ -177,12 +177,12 @@ TEST_F(UnifiedHeapTest, FreeUnreferencedDuringNoGcScope) {
 
 #if !V8_OS_FUCHSIA
 TEST_F(UnifiedHeapTest, TracedReferenceRetainsFromStack) {
-  v8::HandleScope scope(v8_isolate());
+  v8::HandleScope handle_scope(v8_isolate());
   v8::Local<v8::Context> context = v8::Context::New(v8_isolate());
   v8::Context::Scope context_scope(context);
   TracedReference<v8::Object> holder;
   {
-    v8::HandleScope scope(v8_isolate());
+    v8::HandleScope inner_handle_scope(v8_isolate());
     auto local = v8::Object::New(v8_isolate());
     EXPECT_TRUE(local->IsObject());
     holder.Reset(v8_isolate(), local);