Retire StringTracker.

src/isolate.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include <queue>
 #include <set>
 
@@ skipping 889 matching lines @@
   InnerPointerToCodeCache* inner_pointer_to_code_cache() {
     return inner_pointer_to_code_cache_;
   }
 
   GlobalHandles* global_handles() { return global_handles_; }
 
   EternalHandles* eternal_handles() { return eternal_handles_; }
 
   ThreadManager* thread_manager() { return thread_manager_; }
 
-  StringTracker* string_tracker() { return string_tracker_; }
-
   unibrow::Mapping<unibrow::Ecma262UnCanonicalize>* jsregexp_uncanonicalize() {
     return &jsregexp_uncanonicalize_;
   }
 
   unibrow::Mapping<unibrow::CanonicalizationRange>* jsregexp_canonrange() {
     return &jsregexp_canonrange_;
   }
 
   RuntimeState* runtime_state() { return &runtime_state_; }
 
@@ skipping 361 matching lines @@
   UnicodeCache* unicode_cache_;
   Zone runtime_zone_;
   Zone interface_descriptor_zone_;
   InnerPointerToCodeCache* inner_pointer_to_code_cache_;
   GlobalHandles* global_handles_;
   EternalHandles* eternal_handles_;
   ThreadManager* thread_manager_;
   RuntimeState runtime_state_;
   Builtins builtins_;
   bool has_installed_extensions_;
-  StringTracker* string_tracker_;
   unibrow::Mapping<unibrow::Ecma262UnCanonicalize> jsregexp_uncanonicalize_;
   unibrow::Mapping<unibrow::CanonicalizationRange> jsregexp_canonrange_;
   unibrow::Mapping<unibrow::Ecma262Canonicalize>
       regexp_macro_assembler_canonicalize_;
   RegExpStack* regexp_stack_;
   DateCache* date_cache_;
   unibrow::Mapping<unibrow::Ecma262Canonicalize> interp_canonicalize_mapping_;
   CallInterfaceDescriptorData* call_descriptor_data_;
   base::RandomNumberGenerator* random_number_generator_;
   // TODO(hpayer): Remove the following store buffer addresses.
@@ skipping 296 matching lines @@
   }
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_H_