A view that displays search ads.
To show search ads:
1) Create a GADSearchBannerView and add it to your view controller’s view hierarchy.
2) Create a GADSearchRequest ad request object to hold the search query and other search data.
3) Call GADSearchBannerView’s -loadRequest: method with the GADSearchRequest object.
If the banner view is initialized with kGADAdSizeFluid and the corresponding request is created
with dynamic height parameters, this delegate will be called when the ad size changes.