Replace base::str[n]casecmp with helper functions.

device/usb/usb_service_impl.cc

Index: device/usb/usb_service_impl.cc
diff --git a/device/usb/usb_service_impl.cc b/device/usb/usb_service_impl.cc
index ea7ad7f498108d213619935c2de2ddbb107b6fa1..d79d9311dc3ebc0f587416e10162443fd70152e9 100644
--- a/device/usb/usb_service_impl.cc
+++ b/device/usb/usb_service_impl.cc
@@ -127,10 +127,8 @@ bool IsWinUsbInterface(const std::string& device_path) {
   }
 
   USB_LOG(DEBUG) << "Driver for " << device_path << " is " << buffer << ".";
-  if (base::strncasecmp("WinUSB", (const char*)&buffer[0], sizeof "WinUSB") ==
-      0) {
+  if (base::StartsWith(buffer, "WinUSB", base::CompareCase::INSENSITIVE_ASCII))
     return true;
-  }
   return false;
 }