In my case, in Android 4.4, I was getting a black background no matter I set what and this error message in my LogCat: nativeOnDraw failed; clearing to background color.
From Googling, it seems to be because hardware accelerated canvas rendering is not supported in Chromium WebView. I added this line to the WebView to turn off hardware accelerated canvas and now it works.
mWebview.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…