Cleanup usage of HEAP and FACTORY in the cache stub compiler.

src/stub-cache.h

Index: src/stub-cache.h
diff --git a/src/stub-cache.h b/src/stub-cache.h
index 19c4bac282d0a038b60965c5ef8061e710ced593..93ffd7cd5d04bed5aeb8b94dc4e5d968ce256dc4 100644
--- a/src/stub-cache.h
+++ b/src/stub-cache.h
@@ -322,6 +322,8 @@ class StubCache {
     return NULL;
   }
 
+  Isolate* isolate() { return isolate_; }
+  Heap* heap() { return isolate()->heap(); };
 
  private:
   explicit StubCache(Isolate* isolate);
@@ -559,6 +561,8 @@ class StubCompiler BASE_EMBEDDED {
                                     LookupResult* lookup);
 
   Isolate* isolate() { return scope_.isolate(); }
+  Heap* heap() { return isolate()->heap(); }
+  Factory* factory() { return isolate()->factory(); }
 
  private:
   HandleScope scope_;