Introduce additional context to evaluate operations

src/mirror-debugger.js

Index: src/mirror-debugger.js
diff --git a/src/mirror-debugger.js b/src/mirror-debugger.js
index 6b9e9655877a6d979047cab7d0342f6286cef1af..55836ce7ec410041e0bd99f55697fd0c9cbe5e6e 100644
--- a/src/mirror-debugger.js
+++ b/src/mirror-debugger.js
@@ -1533,9 +1533,9 @@ FrameMirror.prototype.scope = function(index) {
 };
 
 
-FrameMirror.prototype.evaluate = function(source, disable_break) {
+FrameMirror.prototype.evaluate = function(source, disable_break, opt_context_object) {
   var result = %DebugEvaluate(this.break_id_, this.details_.frameId(),
-                              source, Boolean(disable_break));
+                              source, Boolean(disable_break), opt_context_object);
   return MakeMirror(result);
 };