Fix cpplint errors in cc/(animation|input|layers|trees|test)/

cc/animation/layer_animation_controller.h

 // Copyright 2012 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 CC_ANIMATION_LAYER_ANIMATION_CONTROLLER_H_
 #define CC_ANIMATION_LAYER_ANIMATION_CONTROLLER_H_
 
 #include "base/basictypes.h"
 #include "base/hash_tables.h"
 #include "base/memory/ref_counted.h"
@@ skipping 75 matching lines @@
 
   void SetAnimationRegistrar(AnimationRegistrar* registrar);
   AnimationRegistrar* animation_registrar() { return registrar_; }
 
   void AddObserver(LayerAnimationValueObserver* observer);
   void RemoveObserver(LayerAnimationValueObserver* observer);
 
  protected:
   friend class base::RefCounted<LayerAnimationController>;
 
-  LayerAnimationController(int id);
+  explicit LayerAnimationController(int id);
   virtual ~LayerAnimationController();
 
  private:
   typedef base::hash_set<int> TargetProperties;
 
   void PushNewAnimationsToImplThread(
       LayerAnimationController* controller_impl) const;
   void RemoveAnimationsCompletedOnMainThread(
       LayerAnimationController* controller_impl) const;
   void PushPropertiesToImplThread(
@@ skipping 38 matching lines @@
   double last_tick_time_;
 
   ObserverList<LayerAnimationValueObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerAnimationController);
 };
 
 }  // namespace cc
 
 #endif  // CC_ANIMATION_LAYER_ANIMATION_CONTROLLER_H_