Added canBecomeKeyView override to RCTScrollView (#60)

RNTester/js/FlatListExample.js

@@ -120,6 +120,7 @@ class FlatListExample extends React.PureComponent<{}, $FlowFixMeState> {
             data={this.state.empty ? [] : filteredData}
             debug={this.state.debug}
             disableVirtualization={!this.state.virtualized}
+            acceptsKeyboardFocus={true} // TODO(macOS ISS#2323203)
             enableSelectionOnKeyPress={true}
             onSelectionEntered={this._handleSelectionEntered}
             getItemLayout={

RNTester/js/ListExampleShared.js

@@ -74,6 +74,7 @@ class ItemComponent extends React.PureComponent<{
         tvParallaxProperties={{
           pressMagnification: 1.1,
         }}
+        acceptsKeyboardFocus={false} // TODO(macOS ISS#2323203)
         style={horizontal ? styles.horizItem : styles.item}>
         <View
           style={[

RNTester/js/RNTesterExampleList.js

@@ -112,6 +112,8 @@ class RNTesterExampleList extends React.Component<Props, $FlowFixMeState> {
               enableEmptySections={true}
               itemShouldUpdate={this._itemShouldUpdate}
               keyboardShouldPersistTaps="handled"
+              acceptsKeyboardFocus={true} // TODO(macOS ISS#2323203)
+              enableSelectionOnKeyPress={true} // TODO(macOS ISS#2323203)
               automaticallyAdjustContentInsets={false}
               keyboardDismissMode="on-drag"
               renderSectionHeader={renderSectionHeader}

React/Views/ScrollView/RCTScrollView.m

@@ -520,6 +520,11 @@ RCT_NOT_IMPLEMENTED(- (instancetype)init)
 }
 
 #if TARGET_OS_OSX // [TODO(macOS ISS#2323203)
+- (BOOL)canBecomeKeyView
+{
+  return [self acceptsKeyboardFocus];
+}
+
 - (CGRect)focusRingMaskBounds
 {
   return [self bounds];