Use HeapHashCountedSet for AnimationPlayerCountedSet

Source/core/animation/AnimationPlayerTest.cpp

 /*
  * Copyright (c) 2013, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 700 matching lines @@
 
 TEST_F(AnimationAnimationPlayerTest, AttachedAnimationPlayers)
 {
     RefPtrWillBePersistent<Element> element = document->createElement("foo", ASSERT_NO_EXCEPTION);
 
     Timing timing;
     RefPtrWillBeRawPtr<Animation> animation = Animation::create(element.get(), nullptr, timing);
     RefPtrWillBeRawPtr<AnimationPlayer> player = timeline->createAnimationPlayer(animation.get());
     player->setStartTime(0);
     timeline->serviceAnimations(TimingUpdateForAnimationFrame);
-    EXPECT_EQ(1, element->activeAnimations()->players().find(player.get())->value);
+    EXPECT_EQ(1U, element->activeAnimations()->players().find(player.get())->value);
 
     player.release();
     Heap::collectAllGarbage();
     EXPECT_TRUE(element->activeAnimations()->players().isEmpty());
 }
 
 TEST_F(AnimationAnimationPlayerTest, HasLowerPriority)
 {
     RefPtrWillBeRawPtr<AnimationPlayer> player1 = timeline->createAnimationPlayer(0);
     RefPtrWillBeRawPtr<AnimationPlayer> player2 = timeline->createAnimationPlayer(0);
     EXPECT_TRUE(AnimationPlayer::hasLowerPriority(player1.get(), player2.get()));
 }
 
 }