AXObjectCache doesn't need to be an ExecutionContextLifecycleObserver

Bug: 1209822
Change-Id: I5aef8983d84ea517aef14134c9d657479dc72e19
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2106533
Auto-Submit: Nate Chapin <japhet@chromium.org>
Commit-Queue: Nektarios Paisios <nektar@chromium.org>
Reviewed-by: Nektarios Paisios <nektar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#750953}

third_party/blink/renderer/core/accessibility/BUILD.gn

@@ -12,7 +12,6 @@ blink_core_sources("accessibility") {
     "ax_context.h",
     "ax_object_cache.cc",
     "ax_object_cache.h",
-    "ax_object_cache_base.cc",
     "ax_object_cache_base.h",
     "axid.h",
   ]

third_party/blink/renderer/core/accessibility/ax_object_cache.cc

@@ -56,11 +56,6 @@ AXObjectCache* AXObjectCache::Create(Document& document) {
   return create_function_(document);
 }
 
-AXObjectCache::AXObjectCache(Document& document)
-    : ExecutionContextLifecycleObserver(document.GetExecutionContext()) {}
-
-AXObjectCache::~AXObjectCache() = default;
-
 namespace {
 
 typedef HashSet<String, CaseFoldingHash> ARIAWidgetSet;
@@ -141,8 +136,4 @@ bool AXObjectCache::IsInsideFocusableElementOrARIAWidget(const Node& node) {
   return false;
 }
 
-void AXObjectCache::Trace(Visitor* visitor) {
-  ExecutionContextLifecycleObserver::Trace(visitor);
-}
-
 }  // namespace blink

third_party/blink/renderer/core/accessibility/ax_object_cache.h

@@ -46,15 +46,12 @@ class LayoutRect;
 class LineLayoutItem;
 class LocalFrameView;
 
-class CORE_EXPORT AXObjectCache : public GarbageCollected<AXObjectCache>,
-                                  public ExecutionContextLifecycleObserver {
-  USING_GARBAGE_COLLECTED_MIXIN(AXObjectCache);
-
+class CORE_EXPORT AXObjectCache : public GarbageCollected<AXObjectCache> {
  public:
   static AXObjectCache* Create(Document&);
 
-  virtual ~AXObjectCache();
-  void Trace(Visitor*) override;
+  virtual ~AXObjectCache() = default;
+  virtual void Trace(Visitor*) {}
 
   virtual void Dispose() = 0;
 
@@ -152,7 +149,7 @@ class CORE_EXPORT AXObjectCache : public GarbageCollected<AXObjectCache>,
 
  private:
   friend class AXObjectCacheBase;
-  AXObjectCache(Document&);
+  AXObjectCache() = default;
 
   static AXObjectCacheCreateFunction create_function_;
   DISALLOW_COPY_AND_ASSIGN(AXObjectCache);

third_party/blink/renderer/core/accessibility/ax_object_cache_base.cc

-// Copyright 2017 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "third_party/blink/renderer/core/accessibility/ax_object_cache_base.h"
-
-#include "third_party/blink/renderer/core/accessibility/ax_object_cache.h"
-#include "third_party/blink/renderer/core/core_export.h"
-
-namespace blink {
-
-AXObjectCacheBase::~AXObjectCacheBase() = default;
-
-AXObjectCacheBase::AXObjectCacheBase(Document& document)
-    : AXObjectCache(document) {}
-
-}  // namespace blink

third_party/blink/renderer/core/accessibility/ax_object_cache_base.h

@@ -24,13 +24,13 @@ class AXObject;
 // new public API methods or similar) and remove this class.
 class CORE_EXPORT AXObjectCacheBase : public AXObjectCache {
  public:
-  ~AXObjectCacheBase() override;
+  ~AXObjectCacheBase() override = default;
 
   virtual AXObject* Get(const Node*) = 0;
   virtual AXObject* GetOrCreate(LayoutObject*) = 0;
 
  protected:
-  AXObjectCacheBase(Document&);
+  AXObjectCacheBase() = default;
   DISALLOW_COPY_AND_ASSIGN(AXObjectCacheBase);
 };
 

third_party/blink/renderer/modules/accessibility/ax_object_cache_impl.cc

@@ -129,8 +129,7 @@ AXObjectCache* AXObjectCacheImpl::Create(Document& document) {
 }
 
 AXObjectCacheImpl::AXObjectCacheImpl(Document& document)
-    : AXObjectCacheBase(document),
-      document_(document),
+    : document_(document),
       modification_count_(0),
       validation_message_axid_(0),
       relation_cache_(std::make_unique<AXRelationCache>(this)),
@@ -1906,8 +1905,6 @@ void AXObjectCacheImpl::DidFinishLifecycleUpdate(const LocalFrameView& view) {
   }
 }
 
-void AXObjectCacheImpl::ContextDestroyed() {}
-
 void AXObjectCacheImpl::Trace(Visitor* visitor) {
   visitor->Trace(document_);
   visitor->Trace(accessible_node_mapping_);

third_party/blink/renderer/modules/accessibility/ax_object_cache_impl.h

@@ -339,9 +339,6 @@ class MODULES_EXPORT AXObjectCacheImpl
   HeapVector<Member<AXEventParams>> notifications_to_post_;
   void PostNotificationsAfterLayout(Document*);
 
-  // ExecutionContextLifecycleObserver overrides.
-  void ContextDestroyed() override;
-
   // Get the currently focused Node element.
   Node* FocusedElement();