Bug 1255133 - Surface the most common JavaScript errors; r=bgrins

--HG--
extra : rebase_source : 19d2c4016ad9a91fbb5d987fe82ae0bf06f29c4e

devtools/client/webconsole/webconsole.js

@@ -17,6 +17,7 @@ Cu.import("resource://devtools/client/shared/browser-loader.js", BrowserLoaderMo
 const promise = require("promise");
 const Services = require("Services");
 const ErrorDocs = require("devtools/server/actors/errordocs");
+const Telemetry = require("devtools/client/shared/telemetry")
 
 loader.lazyServiceGetter(this, "clipboardHelper",
                          "@mozilla.org/widget/clipboardhelper;1",
@@ -242,6 +243,8 @@ function WebConsoleFrame(webConsoleOwner) {
   this.ReactDOM = require("devtools/client/shared/vendor/react-dom");
   this.FrameView = this.React.createFactory(require("devtools/client/shared/components/frame"));
 
+  this._telemetry = new Telemetry();
+
   EventEmitter.decorate(this);
 }
 exports.WebConsoleFrame = WebConsoleFrame;
@@ -1494,6 +1497,11 @@ WebConsoleFrame.prototype = {
     // Add the more info link node to messages that belong to certain categories
     this.addMoreInfoLink(msgBody, scriptError);
 
+    // Collect telemetry data regarding JavaScript errors
+    this._telemetry.logKeyed("DEVTOOLS_JAVASCRIPT_ERROR_DISPLAYED",
+                             scriptError.errorMessageName,
+                             true);
+
     if (objectActors.size > 0) {
       node._objectActors = objectActors;
     }

toolkit/components/telemetry/Histograms.json

@@ -7788,6 +7788,14 @@
     "n_buckets": 20,
     "description": "The amount of time spent in a specific performance tool view, keyed by view name (waterfall, js-calltree, js-flamegraph, etc)."
   },
+  "DEVTOOLS_JAVASCRIPT_ERROR_DISPLAYED": {
+    "alert_emails": ["mphillips@mozilla.com"],
+    "bug_numbers": [1255133],
+    "expires_in_version": "55",
+    "kind": "boolean",
+    "keyed": true,
+    "description": "Measures whether a particular JavaScript error has been displayed in the webconsole."
+  },
   "VIEW_SOURCE_IN_BROWSER_OPENED_BOOLEAN": {
     "alert_emails": ["mozilla-dev-developer-tools@lists.mozilla.org", "jryans@mozilla.com"],
     "expires_in_version": "53",