Allow html5 videos to be played inline.

ios/web/web_state/ui/wk_web_view_configuration_provider.mm

Index: ios/web/web_state/ui/wk_web_view_configuration_provider.mm
diff --git a/ios/web/web_state/ui/wk_web_view_configuration_provider.mm b/ios/web/web_state/ui/wk_web_view_configuration_provider.mm
index c3f6db2d30c689530be997ce0c0cd9d8a5698c96..6191e6b19690546d9f3aa4590f0f0b96f1abb3a6 100644
--- a/ios/web/web_state/ui/wk_web_view_configuration_provider.mm
+++ b/ios/web/web_state/ui/wk_web_view_configuration_provider.mm
@@ -71,6 +71,9 @@ WKWebViewConfigurationProvider::GetWebViewConfiguration() {
                                            WKDataDetectorTypePhoneNumber];
     }
 #endif
+    // API available on iOS 9, although doesn't appear to enable inline playback
+    // Works as intended on iOS 10+
+    [configuration_ setAllowsInlineMediaPlayback:YES];
     // setJavaScriptCanOpenWindowsAutomatically is required to support popups.
     [[configuration_ preferences] setJavaScriptCanOpenWindowsAutomatically:YES];
     [[configuration_ userContentController]