[inspector] migrate stepping related methods to debug-interface

* introduced DebugInterface::PrepareStep and DebugInterface::ClearStepping method.
Inspector calls these methods only on pause and not interseted in calling this for not current break_id so we don't need to expose debug interface with break_id argument and can only check that current break_id is valid.

BUG=chromium:652939,v8:5510
R=yangguo@chromium.org,dgozman@chromium.org

Review-Url: https://chromiumcodereview.appspot.com/2423153002
Cr-Commit-Position: refs/heads/master@{#40450}

src/api.cc

@@ -8811,6 +8811,24 @@ void DebugInterface::ChangeBreakOnException(Isolate* isolate,
                                                     type != NoBreakOnException);
 }
 
+void DebugInterface::PrepareStep(Isolate* v8_isolate, StepAction action) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  ENTER_V8(isolate);
+  CHECK(isolate->debug()->CheckExecutionState());
+  // Clear all current stepping setup.
+  isolate->debug()->ClearStepping();
+  // Prepare step.
+  isolate->debug()->PrepareStep(static_cast<i::StepAction>(action));
+}
+
+void DebugInterface::ClearStepping(Isolate* v8_isolate) {
+  i::Isolate* isolate = reinterpret_cast<i::Isolate*>(v8_isolate);
+  ENTER_V8(isolate);
+  CHECK(isolate->debug()->CheckExecutionState());
+  // Clear all current stepping setup.
+  isolate->debug()->ClearStepping();
+}
+
 Local<String> CpuProfileNode::GetFunctionName() const {
   const i::ProfileNode* node = reinterpret_cast<const i::ProfileNode*>(this);
   i::Isolate* isolate = node->isolate();

src/debug/debug-interface.h

@@ -127,6 +127,17 @@ class DebugInterface {
    */
   static void ChangeBreakOnException(Isolate* isolate,
                                      ExceptionBreakState state);
+
+  enum StepAction {
+    StepOut = 0,   // Step out of the current function.
+    StepNext = 1,  // Step to the next statement in the current function.
+    StepIn = 2,    // Step into new functions invoked or the next statement
+                   // in the current function.
+    StepFrame = 3  // Step into a new frame or return to previous frame.
+  };
+
+  static void PrepareStep(Isolate* isolate, StepAction action);
+  static void ClearStepping(Isolate* isolate);
 };
 
 }  // namespace v8

src/debug/debug.h

@@ -501,8 +501,11 @@ class Debug {
   void Iterate(ObjectVisitor* v);
 
   bool CheckExecutionState(int id) {
-    return is_active() && !debug_context().is_null() && break_id() != 0 &&
+    return CheckExecutionState() && break_id() == id;
-           break_id() == id;
+  }
+
+  bool CheckExecutionState() {
+    return is_active() && !debug_context().is_null() && break_id() != 0;
   }
 
   // Flags and states.

src/inspector/debugger-script.js

@@ -253,43 +253,6 @@ DebuggerScript.currentCallFrames = function(execState, limit)
     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:
 //      [ 0, <v8_result_report> ] in case of success
 //   or [ 1, <general_error_message>, <compiler_message>, <line_number>, <column_number> ] in case of compile error, numbers are 1-based.

src/inspector/debugger_script_externs.js

@@ -61,8 +61,6 @@ var JavaScriptCallFrame;
  */
 var Debug = {};
 
-Debug.clearStepping = function() {}
-
 Debug.clearAllBreakPoints = function() {}
 
 /** @return {!Array<!Script>} */
@@ -192,9 +190,6 @@ BreakEvent.prototype.breakPointsHit = function() {}
 /** @interface */
 function ExecutionState() {}
 
-/** @param {!Debug.StepAction} action */
-ExecutionState.prototype.prepareStep = function(action) {}
-
 /**
  * @param {string} source
  * @param {boolean} disableBreak

src/inspector/v8-debugger.cc

@@ -17,8 +17,6 @@
 namespace v8_inspector {
 
 namespace {
-const char stepIntoV8MethodName[] = "stepIntoStatement";
-const char stepOutV8MethodName[] = "stepOutOfFunction";
 static const char v8AsyncTaskEventEnqueue[] = "enqueue";
 static const char v8AsyncTaskEventEnqueueRecurring[] = "enqueueRecurring";
 static const char v8AsyncTaskEventWillHandle[] = "willHandle";
@@ -315,37 +313,27 @@ void V8Debugger::continueProgram() {
 void V8Debugger::stepIntoStatement() {
   DCHECK(isPaused());
   DCHECK(!m_executionState.IsEmpty());
-  v8::HandleScope handleScope(m_isolate);
+  v8::DebugInterface::PrepareStep(m_isolate, v8::DebugInterface::StepIn);
-  v8::Local<v8::Value> argv[] = {m_executionState};
-  callDebuggerMethod(stepIntoV8MethodName, 1, argv);
   continueProgram();
 }
 
 void V8Debugger::stepOverStatement() {
   DCHECK(isPaused());
   DCHECK(!m_executionState.IsEmpty());
-  v8::HandleScope handleScope(m_isolate);
+  v8::DebugInterface::PrepareStep(m_isolate, v8::DebugInterface::StepNext);
-  v8::Local<v8::Value> argv[] = {m_executionState};
-  callDebuggerMethod("stepOverStatement", 1, argv);
   continueProgram();
 }
 
 void V8Debugger::stepOutOfFunction() {
   DCHECK(isPaused());
   DCHECK(!m_executionState.IsEmpty());
-  v8::HandleScope handleScope(m_isolate);
+  v8::DebugInterface::PrepareStep(m_isolate, v8::DebugInterface::StepOut);
-  v8::Local<v8::Value> argv[] = {m_executionState};
-  callDebuggerMethod(stepOutV8MethodName, 1, argv);
   continueProgram();
 }
 
 void V8Debugger::clearStepping() {
   DCHECK(enabled());
-  v8::HandleScope scope(m_isolate);
+  v8::DebugInterface::ClearStepping(m_isolate);
-  v8::Context::Scope contextScope(debuggerContext());
-
-  v8::Local<v8::Value> argv[] = {v8::Undefined(m_isolate)};
-  callDebuggerMethod("clearStepping", 0, argv);
 }
 
 bool V8Debugger::setScriptSource(
@@ -544,14 +532,11 @@ void V8Debugger::handleProgramBreak(v8::Local<v8::Context> pausedContext,
   m_executionState.Clear();
 
   if (result == V8DebuggerAgentImpl::RequestStepFrame) {
-    v8::Local<v8::Value> argv[] = {executionState};
+    v8::DebugInterface::PrepareStep(m_isolate, v8::DebugInterface::StepFrame);
-    callDebuggerMethod("stepFrameStatement", 1, argv);
   } else if (result == V8DebuggerAgentImpl::RequestStepInto) {
-    v8::Local<v8::Value> argv[] = {executionState};
+    v8::DebugInterface::PrepareStep(m_isolate, v8::DebugInterface::StepIn);
-    callDebuggerMethod(stepIntoV8MethodName, 1, argv);
   } else if (result == V8DebuggerAgentImpl::RequestStepOut) {
-    v8::Local<v8::Value> argv[] = {executionState};
+    v8::DebugInterface::PrepareStep(m_isolate, v8::DebugInterface::StepOut);
-    callDebuggerMethod(stepOutV8MethodName, 1, argv);
   }
 }