Fix marcuswestin#45: Use __has_feature for arc weak support

Author: marcuswestin

WebViewJavascriptBridge/WebViewJavascriptBridge.h

@@ -12,14 +12,6 @@
 #define kCustomProtocolScheme @"wvjbscheme"
 #define kQueueHasMessage      @"__WVJB_QUEUE_MESSAGE__"
 
-#if TARGET_OS_IPHONE && defined(__IPHONE_5_0) && (__IPHONE_OS_VERSION_MAX_ALLOWED >= __IPHONE_5_0)
-    #define WVJB_WEAK_FALLBACK weak
-#elif TARGET_OS_MAC && defined(__MAC_10_7) && (__MAC_OS_X_VERSION_MAX_ALLOWED >= __MAC_10_7)
-    #define WVJB_WEAK_FALLBACK weak
-#else
-    #define WVJB_WEAK_FALLBACK unsafe_unretained
-#endif
-
 #if defined __MAC_OS_X_VERSION_MAX_ALLOWED
     #import <WebKit/WebKit.h>
     #define WVJB_PLATFORM_OSX

WebViewJavascriptBridge/WebViewJavascriptBridge.m

@@ -8,9 +8,16 @@
 
 #import "WebViewJavascriptBridge.h"
 
+#if __has_feature(objc_arc_weak)
+    #define WVJB_WEAK __weak
+#else
+    #define WVJB_WEAK __unsafe_unretained
+#endif
+
+
 @implementation WebViewJavascriptBridge {
-    __weak WVJB_WEBVIEW_TYPE* _webView;
-    __weak id _webViewDelegate;
+    WVJB_WEAK WVJB_WEBVIEW_TYPE* _webView;
+    WVJB_WEAK id _webViewDelegate;
     NSMutableArray* _startupMessageQueue;
     NSMutableDictionary* _responseCallbacks;
     NSMutableDictionary* _messageHandlers;