diff -r 000000000000 -r 6474c204b198 browser/devtools/devtools-clhandler.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/devtools-clhandler.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,77 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
+const kDebuggerPrefs = [
+  "devtools.debugger.remote-enabled",
+  "devtools.debugger.chrome-enabled",
+  "devtools.chrome.enabled"
+];
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "Services", "resource://gre/modules/Services.jsm");
+
+function devtoolsCommandlineHandler() {
+}
+devtoolsCommandlineHandler.prototype = {
+  handle: function(cmdLine) {
+    let consoleFlag = cmdLine.handleFlag("jsconsole", false);
+    let debuggerFlag = cmdLine.handleFlag("jsdebugger", false);
+    if (consoleFlag) {
+      this.handleConsoleFlag(cmdLine);
+    }
+    if (debuggerFlag) {
+      this.handleDebuggerFlag(cmdLine);
+    }
+  },
+
+  handleConsoleFlag: function(cmdLine) {
+    let window = Services.wm.getMostRecentWindow("devtools:webconsole");
+    if (!window) {
+      let devtools = Cu.import("resource://gre/modules/devtools/Loader.jsm", {}).devtools;
+      // Load the browser devtools main module as the loader's main module.
+      Cu.import("resource:///modules/devtools/gDevTools.jsm");
+      let hudservice = devtools.require("devtools/webconsole/hudservice");
+      let console = Cu.import("resource://gre/modules/devtools/Console.jsm", {}).console;
+      hudservice.toggleBrowserConsole().then(null, console.error);
+    } else {
+      window.focus(); // the Browser Console was already open
+    }
+
+    if (cmdLine.state == Ci.nsICommandLine.STATE_REMOTE_AUTO) {
+      cmdLine.preventDefault = true;
+    }
+  },
+
+  handleDebuggerFlag: function(cmdLine) {
+    let remoteDebuggingEnabled = false;
+    try {
+      remoteDebuggingEnabled = kDebuggerPrefs.every((pref) => Services.prefs.getBoolPref(pref));
+    } catch (ex) {
+      Cu.reportError(ex);
+      return;
+    }
+    if (remoteDebuggingEnabled) {
+      Cu.import("resource:///modules/devtools/ToolboxProcess.jsm");
+      BrowserToolboxProcess.init();
+    } else {
+      let errorMsg = "Could not run chrome debugger! You need the following prefs " +
+                     "to be set to true: " + kDebuggerPrefs.join(", ");
+      Cu.reportError(errorMsg);
+      // Dump as well, as we're doing this from a commandline, make sure people don't miss it:
+      dump(errorMsg + "\n");
+    }
+
+    if (cmdLine.state == Ci.nsICommandLine.STATE_REMOTE_AUTO) {
+      cmdLine.preventDefault = true;
+    }
+  },
+
+  helpInfo : "  -jsconsole         Open the Browser Console.\n" +
+             "  -jsdebugger        Open the Browser Toolbox.\n",
+
+  classID: Components.ID("{9e9a9283-0ce9-4e4a-8f1c-ba129a032c32}"),
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsICommandLineHandler]),
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([devtoolsCommandlineHandler]);