Remove some dead code.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 921add3c132ccac6bb7f7adb83712c9e769b362c..ac2e554f85e5112b1a1d72efb0dfe7047eb20969 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -770,7 +770,6 @@ class Isolate {
   void Iterate(ObjectVisitor* v);
   void Iterate(ObjectVisitor* v, ThreadLocalTop* t);
   char* Iterate(ObjectVisitor* v, char* t);
-  void IterateThread(ThreadVisitor* v);
   void IterateThread(ThreadVisitor* v, char* t);
 
 
@@ -923,10 +922,6 @@ class Isolate {
 
   bool fp_stubs_generated() { return fp_stubs_generated_; }
 
-  StaticResource<SafeStringInputBuffer>* compiler_safe_string_input_buffer() {
-    return &compiler_safe_string_input_buffer_;
-  }
-
   Builtins* builtins() { return &builtins_; }
 
   void NotifyExtensionInstalled() {
@@ -1233,7 +1228,6 @@ class Isolate {
   ThreadManager* thread_manager_;
   RuntimeState runtime_state_;
   bool fp_stubs_generated_;
-  StaticResource<SafeStringInputBuffer> compiler_safe_string_input_buffer_;
   Builtins builtins_;
   bool has_installed_extensions_;
   StringTracker* string_tracker_;