Revert of [inspector] migrate stepping related methods to debug-interface

src/inspector/debugger-script.js

Index: src/inspector/debugger-script.js
diff --git a/src/inspector/debugger-script.js b/src/inspector/debugger-script.js
index 9f1a6caafa97b45a5cb05e48720d2307ac782ed3..144830d30e5a51657a55a4078faea6613cdbf1c5 100644
--- a/src/inspector/debugger-script.js
+++ b/src/inspector/debugger-script.js
@@ -251,6 +251,43 @@
     for (var i = 0; i < execState.frameCount() && (!limit || i < limit); ++i)
         frames.push(DebuggerScript._frameMirrorToJSCallFrame(execState.frame(i)));
     return frames;
+}
+
+/**
+ * @param {!ExecutionState} execState
+ */
+DebuggerScript.stepIntoStatement = function(execState)
+{
+    execState.prepareStep(Debug.StepAction.StepIn);
+}
+
+/**
+ * @param {!ExecutionState} execState
+ */
+DebuggerScript.stepFrameStatement = function(execState)
+{
+    execState.prepareStep(Debug.StepAction.StepFrame);
+}
+
+/**
+ * @param {!ExecutionState} execState
+ */
+DebuggerScript.stepOverStatement = function(execState)
+{
+    execState.prepareStep(Debug.StepAction.StepNext);
+}
+
+/**
+ * @param {!ExecutionState} execState
+ */
+DebuggerScript.stepOutOfFunction = function(execState)
+{
+    execState.prepareStep(Debug.StepAction.StepOut);
+}
+
+DebuggerScript.clearStepping = function()
+{
+    Debug.clearStepping();
 }
 
 // Returns array in form: