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",

[yurys, 2013/07/16 07:45:05]

Why is it called updateCallFrameScopes here and rereadScopes in all other
places. Also 'updateFoo' sounds to me more like request to set new value. Why
not rereadCallFrameScopes or getCallFrameScopes. On the other hand there may be
a better verb than 'reread'. In any case we should be consistent in naming. 

[Peter.Rybin, 2013/07/16 12:02:27]

I guess we should discuss naming.

+                "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,

[Peter.Rybin, 2013/07/14 23:13:16]

We may want to make it public, since there is an external request for this
feature.

[yurys, 2013/07/16 07:45:05]

Let's keep it hidden for some time to make sure it sticks in the protocol and
then publish it.

+                "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"
             }
         ]
     }]
 }