Move symbol table from per isolate snapshot to vm isolate snapshot, this reduces the per isolate in…

runtime/vm/symbols.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_SYMBOLS_H_
 #define VM_SYMBOLS_H_
 
 #include "vm/object.h"
 #include "vm/snapshot_ids.h"
 
@@ skipping 519 matching lines @@
 #define DEFINE_SYMBOL_HANDLE_ACCESSOR(t, s, p, a)                              \
   static const String& t() { return *(symbol_handles_[t##Id]); }
   DART_KEYWORD_LIST(DEFINE_SYMBOL_HANDLE_ACCESSOR)
 #undef DEFINE_SYMBOL_HANDLE_ACCESSOR
 
   // Get symbol for scanner keyword.
   static const String& Keyword(Token::Kind keyword);
 
   // Initialize frequently used symbols in the vm isolate.
   static void InitOnce(Isolate* isolate);
+  static void InitOnceFromSnapshot(Isolate* isolate);
+
+  // Add all the symbols that were cached in the VM isolate to this isolate,
+  // we do this when an Isolate is not created from the snapshot so that
+  // we get a unified symbol table that can be be dumped into the VM isolate
+  // snapshot.
+  static void AddPredefinedSymbolsToIsolate();
 
   // Initialize and setup a symbol table for the isolate.
   static void SetupSymbolTable(Isolate* isolate);
 
   // Creates a Symbol given a C string that is assumed to contain
   // UTF-8 encoded characters and '\0' is considered a termination character.
   // TODO(7123) - Rename this to FromCString(....).
   static RawString* New(const char* cstr) {
     return New(cstr, strlen(cstr));
   }
@@ skipping 35 matching lines @@
     kInitialSymtabSize = 2048
   };
 
   static void GetStats(Isolate* isolate,
                        intptr_t* size,
                        intptr_t* capacity);
 
   template<typename StringType>
   static RawString* NewSymbol(const StringType& str);
 
-  // Add the string into the VM isolate symbol table.
-  static void AddToVMIsolate(const String& str);
-
   static intptr_t LookupVMSymbol(RawObject* obj);
   static RawObject* GetVMSymbol(intptr_t object_id);
   static bool IsVMSymbolId(intptr_t object_id) {
     return (object_id >= kMaxPredefinedObjectIds &&
             object_id < (kMaxPredefinedObjectIds + kMaxPredefinedId));
   }
 
   // List of Latin1 characters stored in the vm isolate as symbols
   // in order to make Symbols::FromCharCode fast. This structure is
   // used in generated dart code for direct access to these objects.
   static RawString* predefined_[kNumberOfOneCharCodeSymbols];
 
   // List of handles for predefined symbols.
   static String* symbol_handles_[kMaxPredefinedId];
 
+  friend class Dart;
   friend class String;
   friend class SnapshotReader;
   friend class SnapshotWriter;
   friend class ApiMessageReader;
 
   DISALLOW_COPY_AND_ASSIGN(Symbols);
 };
 
 }  // namespace dart
 
 #endif  // VM_SYMBOLS_H_