[debugger] flood function for stepping before calling it.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index 5434065314d9277df6d7fca33971269330fe2c20..ba77a458b06261088427827d13e5edf42b5b229e 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -1000,7 +1000,7 @@ class ExternalReference BASE_EMBEDDED {
   Address address() const { return reinterpret_cast<Address>(address_); }
 
   // Used to check if single stepping is enabled in generated code.
-  static ExternalReference debug_step_in_fp_address(Isolate* isolate);
+  static ExternalReference debug_last_step_action_address(Isolate* isolate);
 
 #ifndef V8_INTERPRETED_REGEXP
   // C functions called from RegExp generated code.
@@ -1150,8 +1150,11 @@ class CallWrapper {
   virtual void BeforeCall(int call_size) const = 0;
   // Called just after emitting a call, i.e., at the return site for the call.
   virtual void AfterCall() const = 0;
+  // Return whether call needs to check for debug stepping.
+  virtual bool NeedsDebugStepCheck() const { return false; }
 };
 
+
 class NullCallWrapper : public CallWrapper {
  public:
   NullCallWrapper() { }
@@ -1161,6 +1164,16 @@ class NullCallWrapper : public CallWrapper {
 };
 
 
+class CheckDebugStepCallWrapper : public CallWrapper {
+ public:
+  CheckDebugStepCallWrapper() {}
+  virtual ~CheckDebugStepCallWrapper() {}
+  virtual void BeforeCall(int call_size) const {}
+  virtual void AfterCall() const {}
+  virtual bool NeedsDebugStepCheck() const { return true; }
+};
+
+
 // -----------------------------------------------------------------------------
 // Constant pool support