Guard property access to __raven_wrapper__

[scothis]

Accessing the __raven_wrapper__ property in Firefox 48 when run under
Selenium results in the following error:

Uncaught WebDriverError: Permission denied to access property "__raven_wrapper__" (WARNING: The server did not provide any stacktrace information)
    Command duration or timeout: 10 milliseconds
Build info: version: '3.0.0-beta2', revision: '2aa21c1', time: '2016-08-02 15:03:28 -0700'
System info: host: '199-7-164-50', ip: '199.7.164.50', os.name: 'windows', os.arch: 'x86', os.version: '6.2', java.version: '1.8.0_91'
Driver info: org.openqa.selenium.firefox.FirefoxDriver
Capabilities [{browserstack.localIdentifier=travis-3840.1, raisesAccessibilityExceptions=false, browserstack.tunnelIdentifier=travis-3840.1, browserstack.selenium.jar.version=3.0.0-beta2, appBuildId=20160726073904, platform=XP, specificationLevel=0, acceptSslCerts=false, browserstack.key=GpeJcf7DBqk3pHnB3PkZ, browser=firefox, browserVersion=48.0, platformVersion=6.2, acceptSslCert=false, XULappId={ec8030f7-c20a-464f-9b0e-13a3a9e97384}, browserName=Firefox, takesScreenshot=true, browser_version=48.0, platformName=Windows_NT, 64bit=true, browserstack.debug=false, rotatable=false, browserstack.ie.noFlash=false, browserstack.user=dhcole, version=48.0, proxy={}, command_id=1, firefox_binary=c:\Program Files (x86)\firefox 48.0\firefox.exe, browserstack.video=true, orig_os=win8, takesElementScreenshot=true, device=desktop, proxy_type=privoxy}]
Session ID: 8ad81e9d-f345-48a9-b1fe-def338169a10
    at WebDriverError (node_modules/selenium-webdriver/lib/error.js:27:10)
    at Object.checkLegacyResponse (node_modules/selenium-webdriver/lib/error.js:639:15)
    at parseHttpResponse (node_modules/selenium-webdriver/http/index.js:538:13)
    at node_modules/selenium-webdriver/http/index.js:472:11
    at ManagedPromise.invokeCallback_ (node_modules/selenium-webdriver/lib/promise.js:1379:14)
    at TaskQueue.execute_ (node_modules/selenium-webdriver/lib/promise.js:2913:14)
    at TaskQueue.executeNext_ (node_modules/selenium-webdriver/lib/promise.js:2896:21)
    at node_modules/selenium-webdriver/lib/promise.js:2820:25
    at node_modules/selenium-webdriver/lib/promise.js:639:7
From: Task: WebDriver.executeScript()
    at WebDriver.schedule (node_modules/selenium-webdriver/lib/webdriver.js:377:17)
    at WebDriver.executeScript (node_modules/selenium-webdriver/lib/webdriver.js:526:16)
    at WebDriver.driver.load (test/suites/selenium/_init.js:180:14)
    at test/suites/selenium/_init.js:100:14
    at initDriver (test/suites/selenium/_init.js:192:5)
    at test/suites/selenium/_init.js:147:9
    at node_modules/browserstack-local/lib/Local.js:46:11
    at ChildProcess.exithandler (child_process.js:204:7)
    at maybeClose (internal/child_process.js:829:16)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:211:5)

By wrapping the access, we can avoid the error.

Relates to #495

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This change is

[benvinegar]

There's a try/catch block above for __raven__ that also bails and returns func. Rather than repeat that code, lets move the check into that try/catch block.

[benvinegar]

Thanks! If you could address my comment and update, I would be glad to merge.

[scothis]

Thanks @benvinegar, the PR is updated

[benvinegar]

Reviewed 1 of 2 files at r1, 1 of 1 files at r2.
Review status: all files reviewed at latest revision, 1 unresolved discussion.

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