China’s smartphone market has reached saturation, according to a new study by industry analyst IDC that carries potentially significant implications for the global handset industry led by giants like Apple Inc (AAPL.O) and Samsung Electronics Co Ltd . During the first quarter of 2015, smartphone shipments in the world’s most populous country shrank for the first time in six years to 98.8 million, down 4.3 percent from a year earlier, IDC said in report on a Monday, attributing the slump to “market saturation”.