Added support for kCGImageAlphaNoneSkipFirst

Summary:
For kCGImageAlphaNoneSkipFirst type the  FrameType::FORMAT_UNDEFINED == pixelFormat and the returning frame was nil.
Adding support on kCGImageAlphaNoneSkipFirst by
- setting FormatType to RGB32
- adding an if check in order to decide if we are gonna remove the first or the last element.

Reviewed By: foivos-acc, janherling

Differential Revision: D63696938

fbshipit-source-id: 2bb5afa7c759f47f42424af128c9d65172ec895c

impl/ocean/media/imageio/IIOObject.mm

@@ -175,16 +175,10 @@
 		}
 
 		case kCGImageAlphaNoneSkipFirst:
-		{
-			break;
-		}
-
 		case kCGImageAlphaNoneSkipLast:
 		{
 			if (cgColorSpaceMode == kCGColorSpaceModelRGB && bitsPerPixel == 32)
 			{
-				ocean_assert((cgBitmapInfo & kCGBitmapByteOrder32Little) == 0u);
-
 				pixelFormat = FrameType::FORMAT_RGB32;
 			}
 
@@ -321,7 +315,14 @@
 		unsigned int dataPaddingElements = 0u;
 		if (dataPtr != nullptr && Frame::strideBytes2paddingElements(pixelFormat, (unsigned int)(width), (unsigned int)(bytesPerRow), dataPaddingElements))
 		{
-			CV::FrameChannels::removeLastChannel<uint8_t, 4u>((const uint8_t*)(dataPtr), result.data<uint8_t>(), result.width(), result.height(), CV::FrameConverter::CONVERT_NORMAL, dataPaddingElements, result.paddingElements());
+			if (alphaInfo == kCGImageAlphaNoneSkipLast)
+			{
+				CV::FrameChannels::removeLastChannel<uint8_t, 4u>((const uint8_t*)(dataPtr), result.data<uint8_t>(), result.width(), result.height(), CV::FrameConverter::CONVERT_NORMAL, dataPaddingElements, result.paddingElements());
+			}
+			else
+			{
+				CV::FrameChannels::removeFirstChannel<uint8_t, 4u>((const uint8_t*)(dataPtr), result.data<uint8_t>(), result.width(), result.height(), CV::FrameConverter::CONVERT_NORMAL, dataPaddingElements, result.paddingElements());
+			}
 		}
 		else
 		{