[DevTools] Remove Console.messagesCleared event.

third_party/WebKit/Source/platform/v8_inspector/js_protocol.json

 {
     "version": { "major": "1", "minor": "1" },
     "domains": [{
         "domain": "Runtime",
         "description": "Runtime domain exposes JavaScript runtime by means of remote evaluation and mirror objects. Evaluation results are returned as mirror object that expose object type, string representation and unique identifier that can be used for further object reference. Original objects are maintained in memory unless they are either explicitly released or are released along with the other objects in their object group.",
         "types": [
             {
                 "id": "ScriptId",
                 "type": "string",
                 "description": "Unique script identifier."
@@ skipping 751 matching lines @@
                 "name": "messageRepeatCountUpdated",
                 "parameters": [
                     { "name": "count", "type": "integer", "description": "New repeat count value." },
                     { "name": "timestamp", "$ref": "Timestamp", "description": "Timestamp of most recent message in batch.", "hidden": true }
                 ],
                 "description": "Is not issued. Will be gone in the future versions of the protocol.",
                 "deprecated": true
             },
             {
                 "name": "messagesCleared",
-                "description": "Issued when console is cleared. This happens either upon <code>clearMessages</code> command or after page navigation."
+                "description": "Not issued.",
+                "deprecated": true
             }
         ]
     },
     {
         "domain": "Profiler",
         "dependencies": ["Runtime", "Debugger"],
         "hidden": true,
         "types": [
             {
                 "id": "CPUProfileNode",
@@ skipping 209 matching lines @@
             {
                 "name": "heapStatsUpdate",
                 "description": "If heap objects tracking has been started then backend may send update for one or more fragments",
                 "parameters": [
                     { "name": "statsUpdate", "type": "array", "items": { "type": "integer" }, "description": "An array of triplets. Each triplet describes a fragment. The first integer is the fragment index, the second integer is a total count of objects for the fragment, the third integer is a total size of the objects for the fragment."}
                 ]
             }
         ]
     }]
 }