[Interpreter] Enable tracing of bytecode handler dispatches.

src/interpreter/interpreter.h

Index: src/interpreter/interpreter.h
diff --git a/src/interpreter/interpreter.h b/src/interpreter/interpreter.h
index ea50faa02d882c91bee2cdd2912a2cd6e7486db7..e91ab6b1b7ccda13308c4e91d4f392f96548e771 100644
--- a/src/interpreter/interpreter.h
+++ b/src/interpreter/interpreter.h
@@ -49,10 +49,16 @@ class Interpreter {
   void TraceCodegen(Handle<Code> code);
   const char* LookupNameOfBytecodeHandler(Code* code);
 
+  void WriteDispatchCounters();
+
   Address dispatch_table_address() {
     return reinterpret_cast<Address>(&dispatch_table_[0]);
   }
 
+  uintptr_t* bytecode_dispatch_count_table() {
+    return bytecode_dispatch_count_table_.get();
+  }
+
  private:
 // Bytecode handler generator functions.
 #define DECLARE_BYTECODE_HANDLER_GENERATOR(Name, ...) \
@@ -141,6 +147,7 @@ class Interpreter {
 
   Isolate* isolate_;
   Code* dispatch_table_[kDispatchTableSize];
+  v8::base::SmartArrayPointer<uintptr_t> bytecode_dispatch_count_table_;
 
   DISALLOW_COPY_AND_ASSIGN(Interpreter);
 };