If the Picture is not ready, just draw the background

            return;

        }

        // if both mContentWidth and mContentHeight are 0, it means there is no

        // valid Picture passed to WebView yet. This can happen when WebView

        // just starts. Draw the background and return.

        if ((mContentWidth | mContentHeight) == 0 && mHistoryPicture == null) {

            canvas.drawColor(mBackgroundColor);

            return;

        }

        int saveCount = canvas.save();

        if (mInOverScrollMode

                && getSettings().getUseSystemOverscrollBackground()) {