diff --git a/browser/extensions/mortar/moz.build b/browser/extensions/mortar/moz.build
index e53c88c23330..457278335091 100644
--- a/browser/extensions/mortar/moz.build
+++ b/browser/extensions/mortar/moz.build
@@ -4,6 +4,8 @@
 # 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/.
 
+XPCSHELL_TESTS_MANIFESTS += ['test/unit/xpcshell.ini']
+
 SOURCES += [
     'host/rpc.cc',
 ]
diff --git a/browser/extensions/mortar/test/unit/head.js b/browser/extensions/mortar/test/unit/head.js
new file mode 100644
index 000000000000..a69339a91392
--- /dev/null
+++ b/browser/extensions/mortar/test/unit/head.js
@@ -0,0 +1,59 @@
+"use strict";
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+Components.utils.import("resource://gre/modules/Services.jsm");
+// For the following 5 lines of codes, we redirect the
+// path of the "ppapi.js" in addon to the exact file path.
+Components.utils.import("resource://gre/modules/NetUtil.jsm");
+let resHandler = Services.io.getProtocolHandler("resource")
+                         .QueryInterface(Components.interfaces.nsISubstitutingProtocolHandler);
+let dataURI = NetUtil.newURI(do_get_file("."));
+resHandler.setSubstitution("ppapi.js", dataURI);
+
+// Load the script
+load("ppapi-runtime.jsm");
+
+let instanceId = 1;
+let url = "http://example.com";
+let info = {
+    documentURL: "chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai",
+    url,
+    setupJSInstanceObject: false,
+    isFullFrame: false, //pluginElement.ownerDocument.mozSyntheticDocument,
+    arguments: {
+      keys: ["src", "full-frame", "top-level-url"],
+      values: [url, "", url],
+    },
+};
+
+// Head.js is a shared file for all the test_ppb***.js.
+// Right now, window, process and MessageManager are base classes here.
+// Fill in the classes when you need the functions of them
+// and add more mocked classses if you need them in
+// ppapi-runtime.jsm for your tests.
+class Mock_Window {}
+class Mock_Process {}
+class Mock_MessageManager {
+  addMessageListener () {
+  }
+}
+
+// Here the new PPAPIRuntime, Call_PpbFunc and new PPAPIInstance are the
+// core part to invoke codes in ppapi-runtime.jsm.
+let rt = new PPAPIRuntime(new Mock_Process());
+
+function Call_PpbFunc(obj) {
+  if (!obj || !obj.__interface || !obj.__version || !obj.__method) {
+    ok(false, 'invalid JSON');
+  }
+  let fn = obj.__interface + "_" + obj.__method;
+  return rt.table[fn](obj);
+}
+
+// PPAPIInstance constructor(id, rt, info, window, eventHandler, containerWindow, mm)
+let instance = new PPAPIInstance(instanceId, rt, info, new Mock_Window(), null /*docShell.chromeEventHandler*/, null, new Mock_MessageManager());
+
+do_register_cleanup(function () {
+  resHandler.setSubstitution("ppapi.js", null);
+})
+
diff --git a/browser/extensions/mortar/test/unit/test_ppbkeyboard.js b/browser/extensions/mortar/test/unit/test_ppbkeyboard.js
new file mode 100644
index 000000000000..84bc1bd2934a
--- /dev/null
+++ b/browser/extensions/mortar/test/unit/test_ppbkeyboard.js
@@ -0,0 +1,49 @@
+"use strict";
+
+const PPB_TESTCASES = [
+  {"__interface":"PPB_KeyboardInputEvent","__version":"1.2","__method":"IsKeyboardInputEvent","resource":0},
+  {"__interface":"PPB_KeyboardInputEvent","__version":"1.2","__method":"GetKeyCode","key_event":0},
+  {"__interface":"PPB_KeyboardInputEvent","__version":"1.2","__method":"GetCharacterText","character_event":0}
+];
+
+
+class Mock_DomEvent {
+  constructor(eventType) {
+    this.type = eventType;
+    this.timeStamp = 0;
+  }
+}
+
+class Mock_KeyboardInputEvent extends Mock_DomEvent {
+  constructor(eventType, keyCode, charCode) {
+    super(eventType);
+    this.keyCode = keyCode;
+    this.charCode = charCode;
+  }
+}
+
+function run_test() {
+  // We mock a "keydown" event to test "PPB_KeyboardInputEvent".
+  let event = new Mock_KeyboardInputEvent("keydown", 65, 0);
+  // To test PPB_KeyboardInputEvent we need to invoke event resource constructor
+  // in ppapi-runtime.jsm to get a resource id.
+  let eventType = EventTypes.get(event.type);
+  let resource = new eventType.resourceCtor(instance, event);
+  let PP_ResourceID = resource.toJSON();
+
+  PPB_TESTCASES[0].resource = PP_ResourceID;
+  PPB_TESTCASES[1].key_event = PP_ResourceID;
+  Assert.equal(Call_PpbFunc(PPB_TESTCASES[0]), PP_Bool.PP_TRUE);
+  Assert.equal(Call_PpbFunc(PPB_TESTCASES[1]), 65); // 65 is the keyCode when you press 'A'.
+
+  // We mock a "keypress" event to test "PPB_KeyboardInputEvent".
+  event = new Mock_KeyboardInputEvent("keypress", 0, 65);
+  eventType = EventTypes.get(event.type);
+  resource = new eventType.resourceCtor(instance, event);
+  PP_ResourceID = resource.toJSON();
+
+  PPB_TESTCASES[0].resource = PP_ResourceID;
+  PPB_TESTCASES[2].character_event = PP_ResourceID;
+  Assert.equal(Call_PpbFunc(PPB_TESTCASES[0]), PP_Bool.PP_TRUE);
+  Assert.equal(Call_PpbFunc(PPB_TESTCASES[2]).type, PP_VarType.PP_VARTYPE_STRING);
+}
diff --git a/browser/extensions/mortar/test/unit/xpcshell.ini b/browser/extensions/mortar/test/unit/xpcshell.ini
new file mode 100644
index 000000000000..c7fe5b2c5a9c
--- /dev/null
+++ b/browser/extensions/mortar/test/unit/xpcshell.ini
@@ -0,0 +1,8 @@
+[DEFAULT]
+head = head.js
+tail =
+support-files =
+  ../../host/common/opengles2-utils.jsm
+  ../../host/common/ppapi-runtime.jsm
+
+[test_ppbkeyboard.js]