[DevTools] Use InspectorFrontendHost.readyForTest for layout tests.

third_party/WebKit/Source/devtools/protocol.json

 {
     "version": { "major": "1", "minor": "1" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications.",
                 "handlers": ["browser", "renderer"]
             },
             {
                 "name": "disable",
                 "description": "Disables inspector domain notifications."
             }
         ],
         "events": [
             {
-                "name": "evaluateForTestInFrontend",
-                "parameters": [
-                    { "name": "testCallId", "type": "integer" },
-                    { "name": "script", "type": "string" }
-                ]
-            },
-            {
                 "name": "inspect",
                 "parameters": [
                     { "name": "object", "$ref": "Runtime.RemoteObject" },
                     { "name": "hints", "type": "object" }
                 ]
             },
             {
                 "name": "detached",
                 "description": "Fired when remote debugging connection is about to be terminated. Contains detach reason.",
                 "parameters": [
@@ skipping 5153 matching lines @@
                 ],
                 "returns": [
                     { "name": "accessibilityNode", "$ref": "AXNode", "description": "The <code>Accessibility.AXNode</code> for this DOM node, if it exists.", "optional": true }
                 ],
                 "description": "Fetches the accessibility node for this DOM node, if it exists.",
                 "hidden": true
             }
         ]
     }]
 }