DevTools: introduce CSS.setStyleText, we'll migrate setPropertyText to it later.

Source/devtools/protocol.json

 {
     "version": { "major": "1", "minor": "1" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications.",
@@ skipping 3009 matching lines @@
                     { "name": "styleSheetId", "$ref": "StyleSheetId" },
                     { "name": "range", "$ref": "SourceRange" },
                     { "name": "selector", "type": "string" }
                 ],
                 "returns": [
                     { "name": "rule", "$ref": "CSSRule", "description": "The resulting rule after the selector modification." }
                 ],
                 "description": "Modifies the rule selector."
             },
             {
+                "name": "setStyleText",
+                "parameters": [
+                    { "name": "styleSheetId", "$ref": "StyleSheetId" },
+                    { "name": "range", "$ref": "SourceRange" },
+                    { "name": "text", "type": "string" }
+                ],
+                "returns": [
+                    { "name": "rule", "$ref": "CSSStyle", "description": "The resulting style after the selector modification." }
+                ],
+                "description": "Modifies the style text."
+            },
+            {
                 "name": "setMediaText",
                 "parameters": [
                     { "name": "styleSheetId", "$ref": "StyleSheetId" },
                     { "name": "range", "$ref": "SourceRange" },
                     { "name": "text", "type": "string" }
                 ],
                 "returns": [
                     { "name": "media", "$ref": "CSSMedia", "description": "The resulting CSS media rule after modification." }
                 ],
                 "description": "Modifies the rule selector."
@@ skipping 1989 matching lines @@
                 "name": "securityStateChanged",
                 "description": "The security state of the page changed.",
                 "parameters": [
                     { "name": "securityState", "$ref": "SecurityState", "description": "Security state." }
                 ],
                 "handlers": ["browser"]
             }
         ]
     }]
 }