cc: Correct expansion of invalidation for tiles outside of interest rect

cc/resources/picture_pile.h

Index: cc/resources/picture_pile.h
diff --git a/cc/resources/picture_pile.h b/cc/resources/picture_pile.h
index 0e8dca68b198b7f9cdef39d3e73059818fb995fc..539584322c0f48527fdaf9d8701ae5a26c1e96bf 100644
--- a/cc/resources/picture_pile.h
+++ b/cc/resources/picture_pile.h
@@ -51,6 +51,8 @@ class CC_EXPORT PicturePile : public PicturePileBase {
     is_suitable_for_gpu_rasterization_ = false;
   }
 
+  void SetPixelRecordDistanceForTesting(int d) { pixel_record_distance_ = d; }
+
  protected:
   virtual ~PicturePile();
 
@@ -60,6 +62,7 @@ class CC_EXPORT PicturePile : public PicturePileBase {
   void DetermineIfSolidColor();
 
   bool is_suitable_for_gpu_rasterization_;
+  int pixel_record_distance_;
 
   DISALLOW_COPY_AND_ASSIGN(PicturePile);
 };