Replace OStream with std::ostream.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // 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.
 //
@@ skipping 560 matching lines @@
 
 #ifdef DEBUG
   // Check whether the given code contains relocation information that
   // either is position-relative or movable by the garbage collector.
   static bool RequiresRelocation(const CodeDesc& desc);
 #endif
 
 #ifdef ENABLE_DISASSEMBLER
   // Printing
   static const char* RelocModeName(Mode rmode);
-  void Print(Isolate* isolate, OStream& os);  // NOLINT
+  void Print(Isolate* isolate, std::ostream& os);  // NOLINT
 #endif  // ENABLE_DISASSEMBLER
 #ifdef VERIFY_HEAP
   void Verify(Isolate* isolate);
 #endif
 
   static const int kCodeTargetMask = (1 << (LAST_CODE_ENUM + 1)) - 1;
   static const int kPositionMask = 1 << POSITION | 1 << STATEMENT_POSITION;
   static const int kDataMask =
       (1 << CODE_TARGET_WITH_ID) | kPositionMask | (1 << COMMENT);
   static const int kApplyMask;  // Modes affected by apply. Depends on arch.
@@ skipping 512 matching lines @@
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_