DevTools: introduce external service client (behind experiment).

third_party/WebKit/Source/devtools/front_end/externs.js

Index: third_party/WebKit/Source/devtools/front_end/externs.js
diff --git a/third_party/WebKit/Source/devtools/front_end/externs.js b/third_party/WebKit/Source/devtools/front_end/externs.js
index b36803e3ba7cc3711f56765d956f4b4d3d18ec83..de03ada1439c4531cefd96820b74669b5be49508 100644
--- a/third_party/WebKit/Source/devtools/front_end/externs.js
+++ b/third_party/WebKit/Source/devtools/front_end/externs.js
@@ -777,3 +777,18 @@ Gonzales.Node = function()
  * TODO(jsbell): DOMException should be a subclass of Error.
  */
 DOMException.prototype.message;
+
+/**
+ * @constructor
+ * @param {!Object} params
+ */
+var Terminal = function(params) { }
+
+Terminal.prototype = {
+    fit: function() { },
+    linkify: function() { },
+    /** @param {!Element} element */
+    open: function(element) { },
+    /** @param {string} eventName * @param {!Function} handler */
+    on: function(eventName, handler) { }
+}