Add support for testing content in SkyView

sky/engine/tonic/dart_timer_heap.h

Index: sky/engine/tonic/dart_timer_heap.h
diff --git a/sky/engine/tonic/dart_timer_heap.h b/sky/engine/tonic/dart_timer_heap.h
new file mode 100644
index 0000000000000000000000000000000000000000..4b3f9dabbd2b3dbdb5cf63e7e1b8cff905b643da
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+++ b/sky/engine/tonic/dart_timer_heap.h
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+// Copyright 2015 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 SKY_ENGINE_TONIC_DART_TIMER_HEAP_H_
+#define SKY_ENGINE_TONIC_DART_TIMER_HEAP_H_
+
+#include "base/memory/weak_ptr.h"
+#include "base/time/time.h"
+#include "dart/runtime/include/dart_api.h"
+#include "sky/engine/tonic/dart_persistent_value.h"
+#include "sky/engine/wtf/HashMap.h"
+#include "sky/engine/wtf/OwnPtr.h"
+#include "sky/engine/wtf/PassOwnPtr.h"
+
+namespace blink {
+
+class DartTimerHeap {
+ public:
+  DartTimerHeap();
+  ~DartTimerHeap();
+
+  struct Task {
+    DartPersistentValue closure;
+    base::TimeDelta delay;
+    bool repeating = false;
+  };
+
+  int Add(PassOwnPtr<Task> task);
+  void Remove(int id);
+
+ private:
+  void Schedule(int id, PassOwnPtr<Task> task);
+  void Run(int id);
+
+  int next_timer_id_;
+  HashMap<int, OwnPtr<Task>> heap_;
+
+  base::WeakPtrFactory<DartTimerHeap> weak_factory_;
+};
+
+}
+
+#endif  // SKY_ENGINE_TONIC_DART_TIMER_HEAP_H_