[ASDisplayNode] Always return the thread-safe cornerRadius property, …

…even in slow CALayer rounding mode (TextureGroup#749)

- Failing to do so will introduce race conditions in which the property was updated on a background thread but main thread has not executed the block that updates the property of the node's layer. During that window, the layer's property is out-of-date and can't be used.
- After this change, ASDisplayNode's cornerRadius is the only source of truth and users must always use it instead of CALayer's.

CHANGELOG.md

@@ -1,5 +1,6 @@
 ## master
 * Add your own contributions to the next release on the line below this with your name.
+- **Important** ASDisplayNode's cornerRadius is a new thread-safe bridged property that should be preferred over CALayer's. Use the latter at your own risk! [Huy Nguyen](https://github.com/nguyenhuy) [#749](https://github.com/TextureGroup/Texture/pull/749).
 - [ASCellNode] Adds mapping for UITableViewCell focusStyle [Alex Hill](https://github.com/alexhillc) [#727](https://github.com/TextureGroup/Texture/pull/727)
 - [ASNetworkImageNode] Fix capturing self in the block while loading image in ASNetworkImageNode. [Denis Mororozov](https://github.com/morozkin) [#777](https://github.com/TextureGroup/Texture/pull/777)
 - [ASTraitCollection] Add new properties of UITraitCollection to ASTraitCollection. [Yevgen Pogribnyi](https://github.com/ypogribnyi)

Source/ASDisplayNode.h

@@ -659,6 +659,12 @@ extern NSInteger const ASDefaultDrawingPriority;
  * @default ASCornerRoundingTypeDefaultSlowCALayer
  */
 @property (nonatomic, assign)           ASCornerRoundingType cornerRoundingType;  // default=Slow CALayer .cornerRadius (offscreen rendering)
+
+/** @abstract The radius to use when rounding corners of the ASDisplayNode.
+ *
+ * @discussion This property is thread-safe and should always be preferred over CALayer's cornerRadius property,
+ * even if corner rounding type is ASCornerRoundingTypeDefaultSlowCALayer.
+ */
 @property (nonatomic, assign)           CGFloat cornerRadius;                     // default=0.0
 
 @property (nonatomic, assign)           BOOL clipsToBounds;                    // default==NO

Source/Private/ASDisplayNode+UIViewBridge.mm

@@ -186,17 +186,12 @@ - (void)setAlpha:(CGFloat)newAlpha
 - (CGFloat)cornerRadius
 {
   ASDN::MutexLocker l(__instanceLock__);
-  if (_cornerRoundingType == ASCornerRoundingTypeDefaultSlowCALayer) {
-    return self.layerCornerRadius;
-  } else {
-    return _cornerRadius;
-  }
+  return _cornerRadius;
 }
 
 - (void)setCornerRadius:(CGFloat)newCornerRadius
 {
-  ASDN::MutexLocker l(__instanceLock__);
-  [self updateCornerRoundingWithType:_cornerRoundingType cornerRadius:newCornerRadius];
+  [self updateCornerRoundingWithType:self.cornerRoundingType cornerRadius:newCornerRadius];
 }
 
 - (ASCornerRoundingType)cornerRoundingType
@@ -207,8 +202,7 @@ - (ASCornerRoundingType)cornerRoundingType
 
 - (void)setCornerRoundingType:(ASCornerRoundingType)newRoundingType
 {
-  ASDN::MutexLocker l(__instanceLock__);
-  [self updateCornerRoundingWithType:newRoundingType cornerRadius:_cornerRadius];
+  [self updateCornerRoundingWithType:newRoundingType cornerRadius:self.cornerRadius];
 }
 
 - (NSString *)contentsGravity