Change API for using custom JSC

Reviewed By: javache

Differential Revision: D3392219

fbshipit-source-id: ae372dfe9ceab7f7c2da69c731515a05eb3b020a

React/Executors/RCTJSCExecutor.h

@@ -31,18 +31,17 @@ RCT_EXTERN NSString *const RCTJavaScriptContextCreatedNotification;
 @interface RCTJSCExecutor : NSObject <RCTJavaScriptExecutor>
 
 /**
- * Sets a type of JSC library (system or custom) that's used
- * to initialize RCTJSCWrapper.
+ * Returns whether executor uses custom JSC library.
+ * This value is used to initialize RCTJSCWrapper.
  * @default is NO.
  */
-+ (void)setUseCustomJSCLibrary:(BOOL)useCustomLibrary;
+@property (nonatomic, readonly, assign) BOOL useCustomJSCLibrary;
 
 /**
- * Gets a type of JSC library (system or custom) that's used
+ * Inits a new executor instance with given flag that's used
  * to initialize RCTJSCWrapper.
- * @default is NO.
  */
-+ (BOOL)useCustomJSCLibrary;
+- (instancetype)initWithUseCustomJSCLibrary:(BOOL)useCustomJSCLibrary;
 
 /**
  * Create a NSError from a JSError object.

React/Executors/RCTJSCExecutor.mm

@@ -135,6 +135,7 @@ @implementation RCTJSCExecutor
   RandomAccessBundleData _randomAccessBundle;
 
   RCTJSCWrapper *_jscWrapper;
+  BOOL _useCustomJSCLibrary;
 }
 
 @synthesize valid = _valid;
@@ -262,21 +263,15 @@ + (void)runRunLoopThread
   }
 }
 
-static BOOL useCustomJSCLibrary = NO;
-
-+ (void)setUseCustomJSCLibrary:(BOOL)useCustomLibrary
-{
-  useCustomJSCLibrary = useCustomLibrary;
-}
-
-+ (BOOL)useCustomJSCLibrary
+- (instancetype)init
 {
-  return useCustomJSCLibrary;
+  return [self initWithUseCustomJSCLibrary:NO];
 }
 
-- (instancetype)init
+- (instancetype)initWithUseCustomJSCLibrary:(BOOL)useCustomJSCLibrary
 {
   if (self = [super init]) {
+    _useCustomJSCLibrary = useCustomJSCLibrary;
     _valid = YES;
 
     _javaScriptThread = [[NSThread alloc] initWithTarget:[self class]
@@ -333,7 +328,7 @@ - (void)setUp
       return;
     }
 
-    strongSelf->_jscWrapper = RCTJSCWrapperCreate(useCustomJSCLibrary);
+    strongSelf->_jscWrapper = RCTJSCWrapperCreate(strongSelf->_useCustomJSCLibrary);
   }];