Add a method to set system UI visibility for ContentVideoView

android_webview/java/src/org/chromium/android_webview/AwContentViewClient.java

Index: android_webview/java/src/org/chromium/android_webview/AwContentViewClient.java
diff --git a/android_webview/java/src/org/chromium/android_webview/AwContentViewClient.java b/android_webview/java/src/org/chromium/android_webview/AwContentViewClient.java
index 93ae5dd18570244509db28e223967337462d8863..0a7b1b9ff1fc01db5550db93f1e116f7a93c87e0 100644
--- a/android_webview/java/src/org/chromium/android_webview/AwContentViewClient.java
+++ b/android_webview/java/src/org/chromium/android_webview/AwContentViewClient.java
@@ -85,6 +85,10 @@ public class AwContentViewClient extends ContentViewClient implements ContentVid
         return mAwContentsClient.getVideoLoadingProgressView();
     }
 
+    @Override
+    public void setSystemUiVisibility(boolean enterFullscreen) {
+    }
+
     /**
      * Called to show the web contents in fullscreen mode.
      *