[animation-worklet] Implement registerAnimator in worklet scope

third_party/WebKit/Source/modules/compositorworker/AnimatorDefinition.h

+// 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.
+
+#ifndef AnimatorDefinition_h
+#define AnimatorDefinition_h
+
+#include "bindings/core/v8/ScopedPersistent.h"
+#include "platform/heap/Handle.h"
+#include "v8/include/v8.h"
+
+namespace blink {
+
+class ScriptState;
+class Animator;
+
+// This class represents a valid registered Javascript animator. Note that it
+// assumed the argument passed to its constructor have been validated to have
+// proper type.
+// It can be used to instantiate new animators and also to call the Javascript
+// 'animate' callback one a given instance.

[haraken, 2017/03/14 20:33:02]

on a given

[majidvp, 2017/05/18 21:05:03]

Done.

+class AnimatorDefinition final
+    : public GarbageCollectedFinalized<AnimatorDefinition> {
+ public:
+  static AnimatorDefinition* create(ScriptState*,
+                                    v8::Local<v8::Function> constructor,
+                                    v8::Local<v8::Function> animate);
+
+  ~AnimatorDefinition();
+  DEFINE_INLINE_TRACE() {}
+
+  Animator* createInstance();

[haraken, 2017/03/14 20:33:02]

For consistency with https://codereview.chromium.org/2727733002/, I'd prefer
moving createInstance to AnimationWorkletGlobalScope.

Then we can drop m_scriptState from this class.

[majidvp, 2017/05/18 21:05:03]

Done.

+
+ private:
+  AnimatorDefinition(ScriptState*,
+                     v8::Local<v8::Function> constructor,
+                     v8::Local<v8::Function> animate);
+
+  RefPtr<ScriptState> m_scriptState;
+
+  // This object keeps the constructor function, and animate function alive.
+  // It needs to be destroyed to break a reference cycle between it and the
+  // AnimationWorkletGlobalScope.

[haraken, 2017/03/14 20:33:02]

Mention that it is broken at AnimationWorkletGlobalScope::dispose().

[majidvp, 2017/05/18 21:05:03]

Done.

+  ScopedPersistent<v8::Function> m_constructor;
+  ScopedPersistent<v8::Function> m_animate;
+};
+
+}  // namespace blink
+
+#endif  // AnimatorDefinition_h