Moving experimental.metrics API to metricsPrivate

chrome/common/extensions/api/extension_api.json

 [
   {
     "namespace": "extension",
     "types": [
       {
         "id": "MessageSender",
         "type": "object",
         "description": "An object containing information about the script context that sent a message or request.",
         "properties": {
           "tab": {"$ref": "Tab", "optional": true, "description":"This property will <b>only</b> be present when the connection was opened from a tab or content script."},
@@ skipping 5146 matching lines @@
             "name": "callback",
             "optional": true,
             "parameters": [],
             "description": "Called when removal is complete."
           }
         ]
       }
     ]
   },
   {
-    "namespace": "experimental.metrics",
+    "namespace": "metricsPrivate",
     "nodoc": true,
     "types": [
       {
         "id": "MetricType",
         "type":  "object",
         "description": "Describes the type of metric that is to be collected.",
         "properties": {
           "metricName": {"type": "string", "description": "A unique name within the extension for the metric."},
           "type": {
             "type": "string",
             "enum": ["histogram-log", "histogram-linear"],
             "description": "The type of metric, such as 'histogram-log' or 'histogram-linear'."
           },
           "min": {"type": "integer", "description": "The minimum sample value to be recoded.  Must be greater than zero."},
           "max": {"type": "integer", "description": "The maximum sample value to be recoded."},
           "buckets": {"type": "integer", "description": "The number of buckets to use when separating the recorded values."}
         }
       }
     ],
     "functions": [
       {
-        "name": "getEnabled",
-        "type": "function",
-        "description": "Gets the user preference to send UMA and crash reports to Google.",
-        "parameters": [
-          {
-            "type": "function",
-            "name": "callback",
-            "parameters": [
-              {"name": "enabled", "type": "boolean"}
-            ]
-          }
-        ]
-      },
-      {
-        "name": "setEnabled",
-        "type": "function",
-        "description": "Sets the user preference to send UMA and crash reports to Google.",
-        "parameters": [
-          {"name": "enabled", "type": "boolean", "description": "True for setting Chrome to actively send UMA and crash reports, false for disabling this."},
-          {
-            "type": "function",
-            "name": "callback",
-            "parameters": [
-              {
-                "name": "enabled",
-                "type": "boolean",
-                "description": "The actual value set. If it is not the one passed in parameter, the value couldn't be changed (e.g. because of security)."
-              }
-            ]
-          }
-        ]
-      },
-      {
         "name": "recordUserAction",
         "type": "function",
         "description": "Records an action performed by the user.",
         "parameters": [
           {"name": "name", "type": "string"}
         ]
       },
       {
         "name": "recordPercentage",
         "type": "function",
@@ skipping 4031 matching lines @@
                   }
                 }
               }
             ]
           }
         ]
       }
     ]
   }
 ]