Add navigation controls to DevTools screencast view

Source/devtools/protocol.json

 {
     "version": { "major": "1", "minor": "0" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications."
@@ skipping 166 matching lines @@
                     { "name": "secure", "type": "boolean", "description": "True if cookie is secure." },
                     { "name": "session", "type": "boolean", "description": "True in case of session cookie." }
                 ],
                 "hidden": true
             },
             {
                 "id": "ScriptIdentifier",
                 "type": "string",
                 "description": "Unique script identifier.",
                 "hidden": true
+            },
+            {
+                "id": "NavigationEntry",
+                "type": "object",
+                "description": "Navigation history entry.",
+                "properties": [
+                  { "name": "id", "type": "integer", "description": "Unique id of the navigation history entry." },
+                  { "name": "url", "type": "string", "description": "URL of the navigation history entry." },
+                  { "name": "title", "type": "string", "description": "Title of the navigation history entry." }
+                ],
+                "hidden": true
             }
         ],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables page domain notifications."
             },
             {
                 "name": "disable",
                 "description": "Disables page domain notifications."
@@ skipping 25 matching lines @@
                 "description": "Reloads given page optionally ignoring the cache."
             },
             {
                 "name": "navigate",
                 "parameters": [
                     { "name": "url", "type": "string", "description": "URL to navigate the page to." }
                 ],
                 "description": "Navigates current page to the given URL."
             },
             {
+              "name": "getNavigationHistory",
+              "parameters": [],
+              "returns": [
+                { "name": "currentIndex", "type": "integer", "description": "Index of the current navigation history entry." },
+                { "name": "entries", "type": "array", "items": { "$ref": "NavigationEntry"}, "description": "Array of navigation history entries." }
+              ],
+              "description": "Returns navigation history for the current page.",
+              "hidden": true
+            },
+            {
+              "name": "navigateToHistoryEntry",
+              "parameters": [
+                  { "name": "entryId", "type": "integer", "description": "Unique id of the entry to navigate to." }
+              ],
+              "description": "Navigates current page to the given history entry.",
+              "hidden": true
+            },
+            {
                 "name": "getCookies",
                 "returns": [
                     { "name": "cookies", "type": "array", "items": { "$ref": "Cookie"}, "description": "Array of cookie objects." },
                     { "name": "cookiesString", "type": "string", "description": "document.cookie string representation of the cookies." }
                 ],
                 "description": "Returns all browser cookies. Depending on the backend support, will either return detailed cookie information in the <code>cookie</code> field or string cookie representation using <code>cookieString</code>.",
                 "hidden": true
             },
             {
                 "name": "deleteCookie",
@@ skipping 3690 matching lines @@
                 "parameters": [
                     { "name": "value", "type": "array", "items": { "type": "object" } }
                 ]
             },
             {
                 "name": "tracingComplete"
             }
         ]
     }]
 }