appium/appium — pull request #3530 by axemclion (2014-08-30 16:49:23+00:00)
Title: Enabled Performance Logs for iOS

Added performance logs for iOS, similar to what Chromedriver does.

Tested using on both mobile web and hybrid (cordova) app
```javascript
var wd = require('wd');

var b = wd.promiseRemote('http://localhost:4723/wd/hub');
var caps = {
"platformName": "iOS",
"platformVersion": "7.1",
"browserName": "", //"Safari",
"deviceName": "iPhone Simulator",
"app": "/sample/platforms/ios/build/emulator/HelloCordova.app.zip",
"bundleId": "io.cordova.hellocordova",
autoWebview: true,
loggingPrefs: {
performance: 'ALL'
}
};

b.init(caps).then(function() {
return b.log('performance');
}).then(function() {
return require('Q').delay(1000);
}).then(function() {
return b.log('performance');
}).then(function(data) {
console.log(data);
}).fin(function() {
return b.quit();
}).done();
```