[Isolates] Merge crankshaft (r5922 from bleeding_edge).

src/vm-state.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 18 matching lines @@
 #define V8_VM_STATE_H_
 
 #include "isolate.h"
 
 namespace v8 {
 namespace internal {
 
 class VMState BASE_EMBEDDED {
 #ifdef ENABLE_VMSTATE_TRACKING
  public:
-  inline VMState(Isolate* isolate, StateTag state);
+  inline VMState(Isolate* isolate, StateTag tag);
   inline ~VMState();
 
-  StateTag state() { return state_; }
-  void set_external_callback(Address external_callback) {
-    external_callback_ = external_callback;
-  }
-
-  // Used for debug asserts.
-  static bool is_outermost_external() {
-    return Isolate::Current()->current_vm_state() == 0;
-  }
-
-  static StateTag current_state() {
-    VMState* state = Isolate::Current()->current_vm_state();
-    return state ? state->state() : EXTERNAL;
-  }
-
-  static Address external_callback() {
-    VMState* state = Isolate::Current()->current_vm_state();
-    return state ? state->external_callback_ : NULL;
-  }
-
  private:
   Isolate* isolate_;
-  bool disabled_;
-  StateTag state_;
-  VMState* previous_;
-  Address external_callback_;
+  StateTag previous_tag_;
 
 #else
  public:
   VMState(Isolate* isolate, StateTag state) {}
 #endif
 };
 
+
+class ExternalCallbackScope BASE_EMBEDDED {
+#ifdef ENABLE_LOGGING_AND_PROFILING
+ public:
+  inline ExternalCallbackScope(Isolate* isolate, Address callback);
+  inline ~ExternalCallbackScope();
+ private:
+  Isolate* isolate_;
+  Address previous_callback_;
+#else
+ public:
+  ExternalCallbackScope(Isolate* isolate, Address callback) {}
+#endif
+};
+
 } }  // namespace v8::internal
 
 
 #endif  // V8_VM_STATE_H_