ResolutionPolicy has effect here in my case. As you can see for 480 * 800 data below,
dpi = 240
Content Scale Factor: 1.000000
FrameSize HW: 480.000000 800.000000
CustUtils: screenHeight, screenWidth: 480.000000, 800.000000
CustUtils: designScreenHeight, designScreenWidth: 720.000000, 1280.000000 (This is I am setting in CustUtils.cpp, Not glview->setDesignResolutionSize(frameSize.width, frameSize.height, ResolutionPolicy::NO_BORDER)
CustUtils: scaleX, scaleY: 1.000000, 0.666667
Bounding HW= 480.000000 853.333374
Image HW= 720.000000 1280.000000
Here by default image size is , 1280 * 720 but getting scaled. After scaling image size is 853 * 480. Since 853 > 800, image is getting cropped width wise.
Though contentScaleFactor is by default 1, but since my previous designResolution was 1280 * 720, it was not working correctly. Do not get confused by glview->setDesignResolutionSize(frameSize.width, frameSize.height, ResolutionPolicy::NO_BORDER); with mu CustUtils.cpp designResolution HW.
Whatever is happening right now is the thing I wanted to achieve.