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

cc/trees/occlusion_tracker.h

Index: cc/trees/occlusion_tracker.h
diff --git a/cc/trees/occlusion_tracker.h b/cc/trees/occlusion_tracker.h
index f659c313cac8a7232e1bd8443a45d0f7054db933..75382382312ad1cdaed132ac94ad6c248a44db39 100644
--- a/cc/trees/occlusion_tracker.h
+++ b/cc/trees/occlusion_tracker.h
@@ -5,6 +5,8 @@
 #ifndef CC_TREES_OCCLUSION_TRACKER_H_
 #define CC_TREES_OCCLUSION_TRACKER_H_
 
+#include <vector>
+
 #include "base/basictypes.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/region.h"
@@ -93,7 +95,7 @@ class CC_EXPORT OcclusionTrackerBase {
     minimum_tracking_size_ = size;
   }
 
-  // The following is used for visualization purposes. 
+  // The following is used for visualization purposes.
   void set_occluding_screen_space_rects_container(
       std::vector<gfx::Rect>* rects) {
     occluding_screen_space_rects_ = rects;
@@ -106,7 +108,7 @@ class CC_EXPORT OcclusionTrackerBase {
  protected:
   struct StackObject {
     StackObject() : target(0) {}
-    StackObject(const LayerType* target) : target(target) {}
+    explicit StackObject(const LayerType* target) : target(target) {}
     const LayerType* target;
     Region occlusion_from_outside_target;
     Region occlusion_from_inside_target;