DevTools: Show GPU utilization bar on timeline

Source/devtools/protocol.json

 {
     "version": { "major": "1", "minor": "1" },
     "domains": [{
         "domain": "Inspector",
         "hidden": true,
         "types": [],
         "commands": [
             {
                 "name": "enable",
                 "description": "Enables inspector domain notifications."
@@ skipping 2851 matching lines @@
             },
             {
                 "name": "disable",
                 "description": "Disables timeline."
             },
             {
                 "name": "start",
                 "parameters": [
                     { "name": "maxCallStackDepth", "optional": true, "type": "integer", "description": "Samples JavaScript stack traces up to <code>maxCallStackDepth</code>, defaults to 5." },
                     { "name": "bufferEvents", "optional": true, "type": "boolean", "hidden": true, "description": "Whether instrumentation events should be buffered and returned upon <code>stop</code> call." },
-                    { "name": "includeDomCounters", "optional": true, "type": "boolean", "hidden": true, "description": "Whether DOM counters data should be included into timeline events." }
+                    { "name": "includeDomCounters", "optional": true, "type": "boolean", "hidden": true, "description": "Whether DOM counters data should be included into timeline events." },
+                    { "name": "includeGpuEvents", "optional": true, "type": "boolean", "hidden": true, "description": "Whether trace events from GPU process should be collected." }
                 ],
                 "description": "Starts capturing instrumentation events."
             },
             {
                 "name": "stop",
                 "description": "Stops capturing instrumentation events.",
                 "returns": [
                     { "name": "events", "type": "array", "items": { "$ref": "TimelineEvent" }, "optional": true, "hidden": true, "description": "Timeline event record data." }
                 ]
             }
@@ skipping 1129 matching lines @@
                 ]
             }
         ]
     },
     {
         "domain": "Tracing",
         "hidden": true,
         "commands": [
             {
                 "name": "start",
-                "description": "Strart trace events collection.",
+                "description": "Start trace events collection.",
                 "parameters": [
-                    { "name": "categories", "type": "string", "description": "Category/tag filter" }
+                    { "name": "categories", "type": "string", "description": "Category/tag filter" },
+                    { "name": "options", "type": "string", "description": "Tracing options" }
                 ]
             },
             {
                 "name": "end",
                 "description": "Stop trace events collection."
             }
         ],
         "events": [
             {
                 "name": "dataCollected",
                 "parameters": [
                     { "name": "value", "type": "array", "items": { "type": "object" } }
                 ]
             },
             {
                 "name": "tracingComplete"
             }
         ]
     }]
 }