BASELINE: Update Chromium to 85.0.4183.14085-based

Change-Id: Iaa42f4680837c57725b1344f108c0196741f6057
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 78 insertions, 0 deletions

diff --git a/chromium/v8/include/cppgc/internal/write-barrier.h b/chromium/v8/include/cppgc/internal/write-barrier.h
new file mode 100644
index 00000000000..5bf550b0261
--- /dev/null
+++ b/chromium/v8/include/cppgc/internal/write-barrier.h
@@ -0,0 +1,78 @@
+// Copyright 2020 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.
+
+#ifndef INCLUDE_CPPGC_INTERNAL_WRITE_BARRIER_H_
+#define INCLUDE_CPPGC_INTERNAL_WRITE_BARRIER_H_
+
+#include "cppgc/internal/api-constants.h"
+#include "cppgc/internal/process-heap.h"
+#include "v8config.h"  // NOLINT(build/include_directory)
+
+#if defined(CPPGC_CAGED_HEAP)
+#include "cppgc/internal/caged-heap-local-data.h"
+#endif
+
+namespace cppgc {
+namespace internal {
+
+class V8_EXPORT WriteBarrier final {
+ public:
+  static V8_INLINE void MarkingBarrier(const void* slot, const void* value) {
+#if defined(CPPGC_CAGED_HEAP)
+    const uintptr_t start =
+        reinterpret_cast<uintptr_t>(value) &
+        ~(api_constants::kCagedHeapReservationAlignment - 1);
+    const uintptr_t slot_offset = reinterpret_cast<uintptr_t>(slot) - start;
+    if (slot_offset > api_constants::kCagedHeapReservationSize) {
+      // Check if slot is on stack or value is sentinel or nullptr. This relies
+      // on the fact that kSentinelPointer is encoded as 0x1.
+      return;
+    }
+
+    CagedHeapLocalData* local_data =
+        reinterpret_cast<CagedHeapLocalData*>(start);
+    if (V8_UNLIKELY(local_data->is_marking_in_progress)) {
+      MarkingBarrierSlow(value);
+      return;
+    }
+#if defined(CPPGC_YOUNG_GENERATION)
+    GenerationalBarrier(local_data, slot, slot_offset,
+                        reinterpret_cast<uintptr_t>(value) - start);
+#endif
+#else
+    if (V8_LIKELY(!ProcessHeap::IsAnyIncrementalOrConcurrentMarking())) return;
+
+    MarkingBarrierSlowWithSentinelCheck(value);
+#endif  // CPPGC_CAGED_HEAP
+  }
+
+ private:
+  WriteBarrier() = delete;
+
+  static void MarkingBarrierSlow(const void* value);
+  static void MarkingBarrierSlowWithSentinelCheck(const void* value);
+
+#if defined(CPPGC_YOUNG_GENERATION)
+  static V8_INLINE void GenerationalBarrier(CagedHeapLocalData* local_data,
+                                            const void* slot,
+                                            uintptr_t slot_offset,
+                                            uintptr_t value_offset) {
+    const AgeTable& age_table = local_data->age_table;
+
+    // Bail out if the slot is in young generation.
+    if (V8_LIKELY(age_table[slot_offset] == AgeTable::Age::kYoung)) return;
+
+    GenerationalBarrierSlow(local_data, age_table, slot, value_offset);
+  }
+
+  static void GenerationalBarrierSlow(CagedHeapLocalData* local_data,
+                                      const AgeTable& ageTable,
+                                      const void* slot, uintptr_t value_offset);
+#endif
+};
+
+}  // namespace internal
+}  // namespace cppgc
+
+#endif  // INCLUDE_CPPGC_INTERNAL_WRITE_BARRIER_H_