feat(protractor): add browser.getRegisteredMockModules()

Now `browser.getRegisteredMockModules()` returns a list of the functions
or strings that have been registered as mock modules. For troubleshooting.

Closes #1434.

lib/protractor.js

@@ -379,6 +379,17 @@ Protractor.prototype.removeMockModule = function(name) {
   }
 };
 
+/**
+ * Get a list of the current mock modules.
+ *
+ * @return {Array.<!string|Function>}
+ */
+Protractor.prototype.getRegisteredMockModules = function() {
+  return this.mockModules_.map(function(module) {
+    return module.script;
+  });
+};
+
 /**
  * Add the base mock modules used for all Protractor tests.
  *

spec/basic/mockmodule_spec.js

@@ -85,6 +85,16 @@ describe('mock modules', function() {
     expect(element(by.css('[app-version]')).getText()).toEqual('42beta');
   });
 
+  it('should retrieve a list of current mock modules', function() {
+    browser.addMockModule('moduleA', mockModuleA);
+    browser.addMockModule('moduleC', mockModuleC, '2', 'B');
+
+    // Should have 3 mock modules, A, C, and the base.
+    expect(browser.getRegisteredMockModules().length).toBe(3);
+    expect(browser.getRegisteredMockModules()[1]).toEqual(mockModuleA);
+    expect(browser.getRegisteredMockModules()[2]).toEqual(mockModuleC);
+  });
+
   it('should load mock modules after refresh', function() {
     browser.addMockModule('moduleA', mockModuleA);