[debugger] remove mirror cache and v8::Debug::GetMirror.

src/inspector/debugger-script.js

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 89 matching lines @@
     }
     return result;
 }
 
 /**
  * @param {Object} object
  * @return {?RawLocation}
  */
 DebuggerScript.getGeneratorObjectLocation = function(object)
 {
-    var mirror = MakeMirror(object, true /* transient */);
+    var mirror = MakeMirror(object);
     if (!mirror.isGenerator())
         return null;
     var generatorMirror = /** @type {!GeneratorMirror} */(mirror);
     var funcMirror = generatorMirror.func();
     if (!funcMirror.resolved())
         return null;
     var location = generatorMirror.sourceLocation() || funcMirror.sourceLocation();
     var script = funcMirror.script();
     if (script && location) {
         return {
             scriptId: "" + script.id(),
             lineNumber: location.line,
             columnNumber: location.column
         };
     }
     return null;
 }
 
 /**
  * @param {Object} object
  * @return {!Array<!{value: *}>|undefined}
  */
 DebuggerScript.getCollectionEntries = function(object)
 {
-    var mirror = MakeMirror(object, true /* transient */);
+    var mirror = MakeMirror(object);
     if (mirror.isMap())
         return /** @type {!MapMirror} */(mirror).entries();
     if (mirror.isSet() || mirror.isIterator()) {
         var result = [];
         var values = mirror.isSet() ? /** @type {!SetMirror} */(mirror).values() : /** @type {!IteratorMirror} */(mirror).preview();
         for (var i = 0; i < values.length; ++i)
             result.push({ value: values[i] });
         return result;
     }
 }
@@ skipping 395 matching lines @@
     case ScopeType.Closure:
     case ScopeType.Catch:
     case ScopeType.Block:
     case ScopeType.Script:
     case ScopeType.Eval:
     case ScopeType.Module:
         // For transient objects we create a "persistent" copy that contains
         // the same properties.
         // Reset scope object prototype to null so that the proto properties
         // don't appear in the local scope section.
-        var properties = /** @type {!ObjectMirror} */(MakeMirror(scopeObject, true /* transient */)).properties();
+        var properties = /** @type {!ObjectMirror} */(MakeMirror(scopeObject)).properties();
         // Almost always Script scope will be empty, so just filter out that noise.
         // Also drop empty Block, Eval and Script scopes, should we get any.
         if (!properties.length && (scopeType === ScopeType.Script ||
                                    scopeType === ScopeType.Block ||
                                    scopeType === ScopeType.Eval ||
                                    scopeType === ScopeType.Module)) {
             break;
         }
         result = { __proto__: null };
         for (var j = 0; j < properties.length; j++) {
             var name = properties[j].name();
             if (name.length === 0 || name.charAt(0) === ".")
                 continue; // Skip internal variables like ".arguments" and variables with empty name
             result[name] = properties[j].value_;
         }
         break;
     case ScopeType.Global:
     case ScopeType.With:
         result = scopeObject;
         break;
     }
     return result;
 }
 
-// We never resolve Mirror by its handle so to avoid memory leaks caused by Mirrors in the cache we disable it.
-ToggleMirrorCache(false);
-
 return DebuggerScript;
 })();