[animation-worklet] invoke animate callback on mutation signal

third_party/WebKit/Source/modules/compositorworker/Animator.cpp

+// 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 "modules/compositorworker/Animator.h"
+
+#include "bindings/core/v8/V8ScriptRunner.h"
+#include "core/dom/ExecutionContext.h"
+#include "modules/compositorworker/AnimatorDefinition.h"
+#include "platform/bindings/ScriptState.h"
+#include "platform/bindings/V8Binding.h"
+
+namespace blink {
+
+Animator* Animator::Create(v8::Isolate* isolate,
+                           AnimatorDefinition* definition,
+                           v8::Local<v8::Object> instance) {
+  return new Animator(isolate, definition, instance);
+}
+
+Animator::Animator(v8::Isolate* isolate,
+                   AnimatorDefinition* definition,
+                   v8::Local<v8::Object> instance)
+    : definition_(definition), instance_(isolate, instance) {}
+
+Animator::~Animator() {}
+
+DEFINE_TRACE(Animator) {
+  visitor->Trace(definition_);
+}
+
+void Animator::Animate(ScriptState* script_state) const {
+  v8::Isolate* isolate = script_state->GetIsolate();
+
+  v8::Local<v8::Object> instance = instance_.NewLocal(isolate);
+  v8::Local<v8::Function> animate = definition_->AnimateLocal(isolate);
+
+  if (IsUndefinedOrNull(instance) || IsUndefinedOrNull(animate))
+    return;
+
+  ScriptState::Scope scope(script_state);
+  v8::TryCatch block(isolate);
+  block.SetVerbose(true);
+
+  V8ScriptRunner::CallFunction(animate, ExecutionContext::From(script_state),
+                               instance, 0, nullptr, isolate);
+
+  // The animate function may have produced an error!
+  // TODO(majidvp): We should probably just throw here.
+  if (block.HasCaught())
+    return;
+}
+
+}  // namespace blink