Fix hang when logging in to chrome.angrybirds.com

We're apparently sending a bogus redirect flag to WebFrameClient::decidePolicyForNavigation.

BUG=263349

Review URL: https://chromiumcodereview.appspot.com/21399003

git-svn-id: svn://svn.chromium.org/blink/trunk@155288 bbb929c8-8fbe-4397-9dbb-9b2b20218538