[blink/wtf] Make PartitionAlloc's partitions NoDestructor.

No need to call the destructor anywhere, and this is also dangerous in
principle, since raw pointers to the partitions are captured and used
everywhere in blink.

Change-Id: I84f62502003ac2bb3da6d1c48e6e28f7e8c81fb6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2607312Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Benoit L <lizeb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#840193}

third_party/blink/renderer/platform/wtf/DEPS

@@ -15,6 +15,7 @@ include_rules = [
     "+base/memory/ref_counted.h",
     "+base/memory/weak_ptr.h",
     "+base/metrics/histogram_macros.h",
+    "+base/no_destructor.h",
     "+base/numerics",
     "+base/optional.h",
     "+base/process/process_metrics.h",

third_party/blink/renderer/platform/wtf/allocator/partitions.cc

@@ -35,6 +35,7 @@
 #include "base/allocator/partition_allocator/page_allocator.h"
 #include "base/allocator/partition_allocator/partition_alloc_features.h"
 #include "base/debug/alias.h"
+#include "base/no_destructor.h"
 #include "base/strings/safe_sprintf.h"
 #include "base/thread_annotations.h"
 #include "components/crash/core/common/crash_key.h"
@@ -70,35 +71,36 @@ void Partitions::Initialize() {
 // static
 bool Partitions::InitializeOnce() {
 #if !BUILDFLAG(USE_PARTITION_ALLOC_AS_MALLOC)
-  static base::PartitionAllocator fast_malloc_allocator{};
-  fast_malloc_allocator.init(
+  static base::NoDestructor<base::PartitionAllocator> fast_malloc_allocator{};
+  fast_malloc_allocator->init(
       {base::PartitionOptions::Alignment::kRegular,
        base::PartitionOptions::ThreadCache::kEnabled,
        base::PartitionOptions::PCScan::kDisabledByDefault});
 
-  fast_malloc_root_ = fast_malloc_allocator.root();
+  fast_malloc_root_ = fast_malloc_allocator->root();
 #endif  // !BUILDFLAG(USE_PARTITION_ALLOC_AS_MALLOC)
 
-  static base::PartitionAllocator array_buffer_allocator{};
-  static base::PartitionAllocator buffer_allocator{};
-  static base::ThreadUnsafePartitionAllocator layout_allocator{};
+  static base::NoDestructor<base::PartitionAllocator> array_buffer_allocator{};
+  static base::NoDestructor<base::PartitionAllocator> buffer_allocator{};
+  static base::NoDestructor<base::ThreadUnsafePartitionAllocator>
+      layout_allocator{};
 
   base::PartitionAllocGlobalInit(&Partitions::HandleOutOfMemory);
 
-  array_buffer_allocator.init(
+  array_buffer_allocator->init(
       {base::PartitionOptions::Alignment::kRegular,
        base::PartitionOptions::ThreadCache::kDisabled,
        base::PartitionOptions::PCScan::kAlwaysDisabled});
-  buffer_allocator.init({base::PartitionOptions::Alignment::kRegular,
-                         base::PartitionOptions::ThreadCache::kDisabled,
-                         base::PartitionOptions::PCScan::kDisabledByDefault});
-  layout_allocator.init({base::PartitionOptions::Alignment::kRegular,
-                         base::PartitionOptions::ThreadCache::kDisabled,
-                         base::PartitionOptions::PCScan::kAlwaysDisabled});
-
-  array_buffer_root_ = array_buffer_allocator.root();
-  buffer_root_ = buffer_allocator.root();
-  layout_root_ = layout_allocator.root();
+  buffer_allocator->init({base::PartitionOptions::Alignment::kRegular,
+                          base::PartitionOptions::ThreadCache::kDisabled,
+                          base::PartitionOptions::PCScan::kDisabledByDefault});
+  layout_allocator->init({base::PartitionOptions::Alignment::kRegular,
+                          base::PartitionOptions::ThreadCache::kDisabled,
+                          base::PartitionOptions::PCScan::kAlwaysDisabled});
+
+  array_buffer_root_ = array_buffer_allocator->root();
+  buffer_root_ = buffer_allocator->root();
+  layout_root_ = layout_allocator->root();
 
   if (base::features::IsPartitionAllocPCScanEnabled() ||
       base::FeatureList::IsEnabled(kPCScanBlinkPartitions)) {