Introduce additional context to evaluate operations

src/debug-debugger.js

Index: src/debug-debugger.js
diff --git a/src/debug-debugger.js b/src/debug-debugger.js
index d091991a1199eff1ebacd84894563657dd7e97db..bf80735ef8cd6ad11920a46abcebcc85b82e0dc3 100644
--- a/src/debug-debugger.js
+++ b/src/debug-debugger.js
@@ -858,6 +858,7 @@ Debug.debuggerFlags = function() {
   return debugger_flags;
 };
 
+Debug.MakeMirror = MakeMirror;
 
 function MakeExecutionState(break_id) {
   return new ExecutionState(break_id);
@@ -876,9 +877,11 @@ ExecutionState.prototype.prepareStep = function(opt_action, opt_count) {
   return %PrepareStep(this.break_id, action, count);
 }
 
-ExecutionState.prototype.evaluateGlobal = function(source, disable_break) {
-  return MakeMirror(
-      %DebugEvaluateGlobal(this.break_id, source, Boolean(disable_break)));
+ExecutionState.prototype.evaluateGlobal = function(source, disable_break,
+    opt_additional_context) {
+  return MakeMirror(%DebugEvaluateGlobal(this.break_id, source,
+                                         Boolean(disable_break),
+                                         opt_additional_context));
 };
 
 ExecutionState.prototype.frameCount = function() {
@@ -1837,6 +1840,7 @@ DebugCommandProcessor.prototype.evaluateRequest_ = function(request, response) {
   var frame = request.arguments.frame;
   var global = request.arguments.global;
   var disable_break = request.arguments.disable_break;
+  var additional_context = request.arguments.additional_context;
 
   // The expression argument could be an integer so we convert it to a
   // string.
@@ -1850,12 +1854,27 @@ DebugCommandProcessor.prototype.evaluateRequest_ = function(request, response) {
   if (!IS_UNDEFINED(frame) && global) {
     return response.failed('Arguments "frame" and "global" are exclusive');
   }
+  
+  var additional_context_object;
+  if (additional_context) {
+    additional_context_object = {};
+    for (var key in additional_context) {
+      var context_value_handle = additional_context[key];
+      var context_value_mirror = LookupMirror(context_value_handle);
+      if (!context_value_mirror) {
+        return response.failed(
+            "Context object '" + key + "' #" + context_value_handle +
+                "# not found");
+      }
+      additional_context_object[key] = context_value_mirror.value(); 
+    }
+  }
 
   // Global evaluate.
   if (global) {
     // Evaluate in the global context.
-    response.body =
-        this.exec_state_.evaluateGlobal(expression, Boolean(disable_break));
+    response.body = this.exec_state_.evaluateGlobal(
+        expression, Boolean(disable_break), additional_context_object);
     return;
   }
 
@@ -1877,12 +1896,12 @@ DebugCommandProcessor.prototype.evaluateRequest_ = function(request, response) {
     }
     // Evaluate in the specified frame.
     response.body = this.exec_state_.frame(frame_number).evaluate(
-        expression, Boolean(disable_break));
+        expression, Boolean(disable_break), additional_context_object);
     return;
   } else {
     // Evaluate in the selected frame.
     response.body = this.exec_state_.frame().evaluate(
-        expression, Boolean(disable_break));
+        expression, Boolean(disable_break), additional_context_object);
     return;
   }
 };