harmony-scoping: Implement debugger support for script scope.

src/mirror-debugger.js

 // Copyright 2006-2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Handle id counters.
 var next_handle_ = 0;
 var next_transient_handle_ = -1;
 
 // Mirror cache.
 var mirror_cache_ = [];
@@ skipping 177 matching lines @@
 // Different attributes for a property.
 var PropertyAttribute = {};
 PropertyAttribute.None       = NONE;
 PropertyAttribute.ReadOnly   = READ_ONLY;
 PropertyAttribute.DontEnum   = DONT_ENUM;
 PropertyAttribute.DontDelete = DONT_DELETE;
 
 
 // A copy of the scope types from runtime.cc.
 var ScopeType = { Global: 0,
-                  Local: 1,
-                  With: 2,
-                  Closure: 3,
-                  Catch: 4,
-                  Block: 5 };
+                  Script: 1,

[yurys, 2014/11/14 12:25:32]

This will break DevTools code as we rely on these constants in [1]. Please add
the new constant to the end of the list. Also I think DevTools code should be
prepared to work with the new scope type before landing this change. Andrey, can
you take care of this?

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

[aandrey, 2014/11/14 12:35:22]

Can you add the new scope at the end. Our code depends on the numbers:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

Also please add a comment that enumeration values should be backward compatible.

[Dmitry Lomov (no reviews), 2014/11/14 13:56:51]

Done.

+                  Local: 2,
+                  With: 3,
+                  Closure: 4,
+                  Catch: 5,
+                  Block: 6 };
 
 
 // Mirror hierarchy:
 //   - Mirror
 //     - ValueMirror
 //       - UndefinedMirror
 //       - NullMirror
 //       - NumberMirror
 //       - StringMirror
 //       - SymbolMirror
@@ skipping 2073 matching lines @@
   return this.scope_index_;
 };
 
 
 ScopeMirror.prototype.scopeType = function() {
   return this.details_.type();
 };
 
 
 ScopeMirror.prototype.scopeObject = function() {
-  // For local and closure scopes create a transient mirror as these objects are
-  // created on the fly materializing the local or closure scopes and
-  // therefore will not preserve identity.
+  // For local, closure and script scopes create a transient mirror
+  // as these objects are created on the fly materializing the local
+  // or closure scopes and therefore will not preserve identity.
   var transient = this.scopeType() == ScopeType.Local ||
-                  this.scopeType() == ScopeType.Closure;
+                  this.scopeType() == ScopeType.Closure ||
+                  this.scopeType() == ScopeType.Script;
   return MakeMirror(this.details_.object(), transient);
 };
 
 
 ScopeMirror.prototype.setVariableValue = function(name, new_value) {
   this.details_.setVariableValueImpl(name, new_value);
 };
 
 
 /**
@@ skipping 703 matching lines @@
   }
   if (!NUMBER_IS_FINITE(value)) {
     if (value > 0) {
       return 'Infinity';
     } else {
       return '-Infinity';
     }
   }
   return value;
 }