Renamed "symbols" to "internalized strings" throughout the code base,

src/variables.cc

Index: src/variables.cc
diff --git a/src/variables.cc b/src/variables.cc
index 916121791798489d434acb8637f088327891d62a..488da42ce665ed7322ca7f53e27fc3ec9c109e58 100644
--- a/src/variables.cc
+++ b/src/variables.cc
@@ -76,7 +76,7 @@ Variable::Variable(Scope* scope,
     initialization_flag_(initialization_flag),
     interface_(interface) {
   // Names must be canonicalized for fast equality checks.
-  ASSERT(name->IsSymbol());
+  ASSERT(name->IsInternalizedString());
   // Var declared variables never need initialization.
   ASSERT(!(mode == VAR && initialization_flag == kNeedsInitialization));
 }