Use ParentFrameTaskRunners for encodeImageOnEncoderThread

third_party/WebKit/Source/core/workers/ParentFrameTaskRunners.h

 // Copyright 2016 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.
 
 #ifndef ParentFrameTaskRunners_h
 #define ParentFrameTaskRunners_h
 
 #include "core/CoreExport.h"
 #include "core/dom/TaskRunnerHelper.h"
 #include "core/frame/LocalFrameLifecycleObserver.h"
@@ skipping 13 matching lines @@
 // on the parent context thread (i.e. MainThread) on construction time, rather
 // than being done lazily.
 //
 // This observes LocalFrame lifecycle only for in-process worker cases (i.e.
 // only when a non-null LocalFrame is given).
 class CORE_EXPORT ParentFrameTaskRunners final : public GarbageCollectedFinalized<ParentFrameTaskRunners>, public LocalFrameLifecycleObserver {
     USING_GARBAGE_COLLECTED_MIXIN(ParentFrameTaskRunners);
     WTF_MAKE_NONCOPYABLE(ParentFrameTaskRunners);
 
 public:
-    // LocalFrame could be nullptr if the worker is not associated with a
-    // particular local frame.
-    explicit ParentFrameTaskRunners(LocalFrame*);
+    static ParentFrameTaskRunners* create(LocalFrame* frame)
+    {
+        return new ParentFrameTaskRunners(frame);
+    }
 
     // Might return nullptr for unsupported task types.
     WebTaskRunner* get(TaskType);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     using TaskRunnerHashMap = HashMap<TaskType, WebTaskRunner*, WTF::IntHash<TaskType>, TaskTypeTraits>;
 
+    // LocalFrame could be nullptr if the worker is not associated with a
+    // particular local frame.
+    explicit ParentFrameTaskRunners(LocalFrame*);
+
     void contextDestroyed() override;
 
     Mutex m_taskRunnersMutex;
     TaskRunnerHashMap m_taskRunners;
 };
 
 } // namespace blink
 
 #endif // ParentFrameTaskRunners_h