Summary:
Addresses #1534
When an image has a known width, but a height of 0 (which can happen if `flex: 1` is set on the `Image` element), `RCTDownloadManager` attempts to scale it to an invalid size, which results in a `NULL` `CGContextRef` and some scary warnings from UIKit:
```
<Error>: CGContextTranslateCTM: invalid context 0x0. This is a serious error. This application, or a library it uses, is using an invalid context and is thereby contributing to an overall degradation of system stability and reliability. This notice is a courtesy: please fix this problem. It will become a fatal error in an upcoming update.
```
This adds a check for zero width or height to the `RCTClipRect` function. If either dimension is zero, it is calculated based on the aspect ratio of the source image. This ensures that we don't try to create an invalid `CGContextRef`, and that images with an unknown dimension are still scaled, blended, etc.
Closes https://github.com/facebook/react-native/pull/2278
Github Author: Yusef Napora <yusef@napora.org>
Summary:
Merged RCTStaticImage with our internal RKStaticImage and ported over logic where assets are loaded at the optimal size and reloaded if the view size changes.