[debugger] remove step count parameter from prepare step.

src/runtime/runtime.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_RUNTIME_RUNTIME_H_
 #define V8_RUNTIME_RUNTIME_H_
 
 #include "src/allocation.h"
 #include "src/objects.h"
 #include "src/unicode.h"
@@ skipping 165 matching lines @@
   F(DebugPrintScopes, 0, 1)                    \
   F(GetThreadCount, 1, 1)                      \
   F(GetThreadDetails, 2, 1)                    \
   F(SetBreakPointsActive, 1, 1)                \
   F(GetBreakLocations, 2, 1)                   \
   F(SetFunctionBreakPoint, 3, 1)               \
   F(SetScriptBreakPoint, 4, 1)                 \
   F(ClearBreakPoint, 1, 1)                     \
   F(ChangeBreakOnException, 2, 1)              \
   F(IsBreakOnException, 1, 1)                  \
-  F(PrepareStep, 3, 1)                         \
+  F(PrepareStep, 2, 1)                         \
   F(ClearStepping, 0, 1)                       \
   F(DebugEvaluate, 6, 1)                       \
   F(DebugEvaluateGlobal, 4, 1)                 \
   F(DebugGetLoadedScripts, 0, 1)               \
   F(DebugReferencedBy, 3, 1)                   \
   F(DebugConstructedBy, 2, 1)                  \
   F(DebugGetPrototype, 1, 1)                   \
   F(DebugSetScriptSource, 2, 1)                \
   F(FunctionGetInferredName, 1, 1)             \
   F(FunctionGetDebugName, 1, 1)                \
@@ skipping 1054 matching lines @@
 
 class DeclareGlobalsEvalFlag : public BitField<bool, 0, 1> {};
 class DeclareGlobalsNativeFlag : public BitField<bool, 1, 1> {};
 STATIC_ASSERT(LANGUAGE_END == 3);
 class DeclareGlobalsLanguageMode : public BitField<LanguageMode, 2, 2> {};
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_RUNTIME_RUNTIME_H_