[heap] Remove js call rate heuristic from memory reducer.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 157c3f90215b27b6a607104d4c616d732e11c7c2..22888fc7f2e90e1b07a380208a79a27689402bc7 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -1073,12 +1073,6 @@ class Isolate {
     return id;
   }
 
-  void IncrementJsCallsFromApiCounter() { ++js_calls_from_api_counter_; }
-
-  unsigned int js_calls_from_api_counter() {
-    return js_calls_from_api_counter_;
-  }
-
   // Get (and lazily initialize) the registry for per-isolate symbols.
   Handle<JSObject> GetSymbolRegistry();
 
@@ -1416,9 +1410,6 @@ class Isolate {
 
   int next_optimization_id_;
 
-  // Counts javascript calls from the API. Wraps around on overflow.
-  unsigned int js_calls_from_api_counter_;
-
 #if TRACE_MAPS
   int next_unique_sfi_id_;
 #endif