spatnav: Change the data type of distance from long long to double

Source/core/page/SpatialNavigation.h

Index: Source/core/page/SpatialNavigation.h
diff --git a/Source/core/page/SpatialNavigation.h b/Source/core/page/SpatialNavigation.h
index 46851685c5b062be0be014db67a4db37f137440a..c4a5cfb46bce776ced83383ade66fd175b5e0d86 100644
--- a/Source/core/page/SpatialNavigation.h
+++ b/Source/core/page/SpatialNavigation.h
@@ -33,9 +33,9 @@ class LocalFrame;
 class HTMLAreaElement;
 class HTMLFrameOwnerElement;
 
-inline long long maxDistance()
+inline double maxDistance()
 {
-    return std::numeric_limits<long long>::max();
+    return std::numeric_limits<double>::max();
 }
 
 inline int fudgeFactor()
@@ -121,7 +121,7 @@ public:
     RawPtrWillBeMember<Node> visibleNode;
     RawPtrWillBeMember<Node> focusableNode;
     RawPtrWillBeMember<Node> enclosingScrollableBox;
-    long long distance;
+    double distance;
     RectsAlignment alignment;
     LayoutRect rect;
     bool isOffscreen;