Can I charge my Samsung Omnia W with MacBook Pro USB port? Currently, I am using a Samsung Omnia W and mostly I am using my 2013 MacBook Pro's USB port for charging it.

Is it fine for charging the battery in the mobile phone? Sometimes, I have received a 'high power consumption' warning (from USB port) on laptop as warning.

What is the power output of the USB port compared to the mobile's input power for the battery?
Apple computers and displays without USB-C ports will strictly adhere to USB standards for all non-Apple hardware, so you will be limited to 5 V at 500 mA for charging your Samsung phone. 


http://support.apple.com/kb/HT4049


Third party chargers or wall adapters will be needed if your device is requesting or using more than 500 mA since Apple will shut USB ports that exceed the spec and are not Apple to Apple. 

Also, this USB over-current condition is safe, expected and like a modern circuit breaker, you unplug the device and reset the circuit except for USB on Mac, the reset happens immediately when you unplug the offending device. Unless your device has a sync only setting, you'll need a special USB cable to sync and have to charge it elsewhere than from your Mac.