convert disassembler to use OStream

src/disassembler.h

Index: src/disassembler.h
diff --git a/src/disassembler.h b/src/disassembler.h
index f65f5385791d6ba84104d346ebb4d28283f3cf3e..9b53166f2bb0ba7523dd997b560cd1e7a1f4c59a 100644
--- a/src/disassembler.h
+++ b/src/disassembler.h
@@ -12,22 +12,12 @@ namespace internal {
 
 class Disassembler : public AllStatic {
  public:
-  // Print the bytes in the interval [begin, end) into f.
-  static void Dump(FILE* f, byte* begin, byte* end);
-
   // Decode instructions in the the interval [begin, end) and print the
-  // code into f. Returns the number of bytes disassembled or 1 if no
+  // code into os. Returns the number of bytes disassembled or 1 if no
   // instruction could be decoded.
-  static int Decode(Isolate* isolate, FILE* f, byte* begin, byte* end);
-
-  // Decode instructions in code.
-  static void Decode(FILE* f, Code* code);
- private:
-  // Decode instruction at pc and print disassembled instruction into f.
-  // Returns the instruction length in bytes, or 1 if the instruction could
-  // not be decoded.  The number of characters written is written into
-  // the out parameter char_count.
-  static int Decode(FILE* f, byte* pc, int* char_count);
+  // the code object is used for name resolution and may be null.
+  static int Decode(Isolate* isolate, OStream* os, byte* begin, byte* end,
+                    Code* code = NULL);
 };
 
 } }  // namespace v8::internal