The Windows Phone 8.1 GDR1 update removes “Google” search option from browsers in some markets. According to the documentation for the device the update removes all search options except for Bing in certain supported markets.
According to documentation found on the Windows Phone Dev Center website for the GDR1 update, "the only search provider included on the phone is Bing." "Yandex" is the search engine provided in Turkey and Russia, while in countries where Bing is not supported, manufacturers will give users an option to choose between a couple of search engines.
Microsoft is promoting Bing with the new update, in an effort to grab more ad revenue from Google. Microsoft stated in a blog post:
"By default, the only search provider included on the phone is Bing. The search provider used in the browser is always the same as the one launched by the hardware search button. However, in certain markets OEMs must specify a different search provider as the default search provider for Windows Phone. For more information about the default search provider that OEMs must set for these markets, see the section Default search providers for specific markets.
The phone automatically determines whether Bing is supported based on the browser and search language. This language is derived from the default region format, and can be modified by the user. If the phone’s browser and search language are set to a language that Bing supports, any search providers specified by the OEM will be hidden from the Internet Explorer screen in Settings, and both the hardware search button and search in the browser will always use Bing. Partners cannot control or change this determination. Windows Phone reserves the right to update the list of supported languages, and therefore override or hide custom OEM search providers, at any time."
The new Windows Phone 8.1 GDR1 also brings support for larger displays, from 6.01-inches up to 7-inches and includes support for 1280 x 768 WXGA resolution. The update also allows users to organize their Start screen with Folder support. Microsoft’s voice assistant Cortana gets additional features, including new natural language scenarios, snooze times for reminders and more. Microsoft has also added the ability to make Cortana hands-free, by adding “call Cortana” feature from a car’s contact list.
Source: Windows Phone Dev Center