Increase pretenure ratio from 60% to 85%

As pretenure-call-new comes online, this is a better performing ratio
overall.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/196383032

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20041 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.cc

@@ -12755,7 +12755,7 @@ void JSObject::TransitionElementsKind(Handle<JSObject> object,
 }
 
 
-const double AllocationSite::kPretenureRatio = 0.60;
+const double AllocationSite::kPretenureRatio = 0.85;
 
 
 void AllocationSite::ResetPretenureDecision() {