The site also mentions that within the Android ecosystem, Samsung accounts for 40 percent of all phones sold. The closest competitor is Huawei, at a distant second place with a marketshare of only 6.6 percent.
If Samsung were to split from Android, it would pull the carpet from under Google's feet. Apple and Samsung take roughly 98% of all revenue from smartphones sold, leaving just 2% to HTC, Sony, Motorola, LG and more. Even more worrying for Google, Samsung could choose to release a custom version of Android - like Amazon did with the Kindle Fire - which runs it's own software and bares little resemblance to Android. If Samsung chose to follow this path, it could also choose to block Google out and decrease their revenue from mobile ads significantly.Source: Neowin
Google does still have Motorola - which it purchased for an eye-watering $12.5 billion last year - to manufacture phones, however, the power Motorola yields is small; Google has openly admitted that the partnership has not yet started bearing fruit, with Google deciding to manufacture their Nexus 7 tablet with ASUS and their Nexus phone with LG. Google is rumoured to be creating an "X phone" which will compete - and, Google hopes, beat - their rivals at Samsung.