Support re-reading scope variables in protocol and on backed.

Source/devtools/protocol.json

 {
     "version": { "major": "1", "minor": "0" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications."
@@ skipping 3004 matching lines @@
                 "name": "setVariableValue",
                 "parameters": [
                     { "name": "scopeNumber", "type": "integer", "description": "0-based number of scope as was listed in scope chain. Only 'local', 'closure' and 'catch' scope types are allowed. Other scopes could be manipulated manually." },
                     { "name": "variableName", "type": "string", "description": "Variable name." },
                     { "name": "newValue", "$ref": "Runtime.CallArgument", "description": "New variable value." },
                     { "name": "callFrameId", "$ref": "CallFrameId", "optional": true, "description": "Id of callframe that holds variable." },
                     { "name": "functionObjectId", "$ref": "Runtime.RemoteObjectId", "optional": true, "description": "Object id of closure (function) that holds variable." }
                 ],
                 "hidden": true,
                 "description": "Changes value of variable in a callframe or a closure. Either callframe or function must be specified. Object-based scopes are not supported and must be mutated manually."
+            },
+            {
+                "name": "updateCallFrameScopes",
+                "parameters": [
+                    { "name": "callFrameId", "$ref": "CallFrameId", "description": "Call frame id that scopes must be re-read of." }
+                ],
+                "returns": [
+                    { "name": "scopeChain", "type": "array", "items": { "$ref": "Scope" }, "description": "Scope chain for this call frame." }
+                ],
+                "hidden": true,
+                "description": "Gets a fresh copy of variable scopes of a call frame currently on stack."
             }
         ],
         "events": [
             {
                 "name": "globalObjectCleared",
                 "description": "Called when global has been cleared and debugger client should reset its state. Happens upon navigation or reload."
             },
             {
                 "name": "scriptParsed",
                 "parameters": [
@@ skipping 738 matching lines @@
                 ]
             }
         ],
         "events": [
             {
                 "name": "layerTreeDidChange"
             }
         ]
     }]
 }