Fix crashes when using WKWebView implementation on iOS 9.

Fixes apache#323. Fixes apache#324.

Author: dpa99c

README.md

@@ -147,9 +147,9 @@ instance, or the system browser.
     - __toolbar__:  set to `yes` or `no` to turn the toolbar on or off for the InAppBrowser (defaults to `yes`)
     - __toolbarcolor__: set as a valid hex color string, for example: `#00ff00`, to change from the default color of the toolbar. Only applicable if toolbar is not disabled.
     - __toolbartranslucent__:  set to `yes` or `no` to make the toolbar translucent(semi-transparent)  (defaults to `yes`). Only applicable if toolbar is not disabled.
-    - __enableViewportScale__:  Set to `yes` or `no` to prevent viewport scaling through a meta tag (defaults to `no`). Only applicable to UIWebView (`usewkwebview=no`).
-    - __mediaPlaybackRequiresUserAction__: Set to `yes` to prevent HTML5 audio or video from autoplaying (defaults to `no`). Only applicable to UIWebView (`usewkwebview=no`).
-    - __allowInlineMediaPlayback__: Set to `yes` or `no` to allow in-line HTML5 media playback, displaying within the browser window rather than a device-specific playback interface. The HTML's `video` element must also include the `webkit-playsinline` attribute (defaults to `no`) Only applicable to UIWebView (`usewkwebview=no`).
+    - __enableViewportScale__:  Set to `yes` or `no` to prevent viewport scaling through a meta tag (defaults to `no`). Only applicable to UIWebView (`usewkwebview=no`) and WKWebView (`usewkwebview=yes`) on iOS 10+.
+    - __mediaPlaybackRequiresUserAction__: Set to `yes` to prevent HTML5 audio or video from autoplaying (defaults to `no`). Applicable to UIWebView (`usewkwebview=no`) and WKWebView (`usewkwebview=yes`).
+    - __allowInlineMediaPlayback__: Set to `yes` or `no` to allow in-line HTML5 media playback, displaying within the browser window rather than a device-specific playback interface. The HTML's `video` element must also include the `webkit-playsinline` attribute (defaults to `no`). Applicable to UIWebView (`usewkwebview=no`) and WKWebView (`usewkwebview=yes`).
     - __keyboardDisplayRequiresUserAction__: Set to `yes` or `no` to open the keyboard when form elements receive focus via JavaScript's `focus()` call (defaults to `yes`). Only applicable to UIWebView (`usewkwebview=no`).
     - __suppressesIncrementalRendering__: Set to `yes` or `no` to wait until all new view content is received before being rendered (defaults to `no`). Only applicable to UIWebView (`usewkwebview=no`).
     - __presentationstyle__:  Set to `pagesheet`, `formsheet` or `fullscreen` to set the [presentation style](http://developer.apple.com/library/ios/documentation/UIKit/Reference/UIViewController_Class/Reference/Reference.html#//apple_ref/occ/instp/UIViewController/modalPresentationStyle) (defaults to `fullscreen`).

src/ios/CDVWKInAppBrowser.m

@@ -664,14 +664,20 @@ - (void)createViews
     [configuration.userContentController addScriptMessageHandler:self name:IAB_BRIDGE_NAME];
 
     //WKWebView options
-    configuration.ignoresViewportScaleLimits = _browserOptions.enableviewportscale;
     configuration.allowsInlineMediaPlayback = _browserOptions.allowinlinemediaplayback;
-    if(_browserOptions.mediaplaybackrequiresuseraction == YES){
-        configuration.mediaTypesRequiringUserActionForPlayback = WKAudiovisualMediaTypeAll;
-    }else{
-        configuration.mediaTypesRequiringUserActionForPlayback = WKAudiovisualMediaTypeNone;
+    if (@available(iOS 10.0, *)) {
+        configuration.ignoresViewportScaleLimits = _browserOptions.enableviewportscale;
+        if(_browserOptions.mediaplaybackrequiresuseraction == YES){
+            configuration.mediaTypesRequiringUserActionForPlayback = WKAudiovisualMediaTypeAll;
+        }else{
+            configuration.mediaTypesRequiringUserActionForPlayback = WKAudiovisualMediaTypeNone;
+        }
+    }else{ // iOS 9
+        configuration.mediaPlaybackRequiresUserAction = _browserOptions.mediaplaybackrequiresuseraction;
     }
 
+    
+
     self.webView = [[WKWebView alloc] initWithFrame:webViewBounds configuration:configuration];
 
     [self.view addSubview:self.webView];