Merge "Do not draw background if the background drawable is null"

        DisplayListCanvas canvas = mFrameAndBackdropNode.start(width, height);

        final Drawable drawable = mUserCaptionBackgroundDrawable != null

                ? mUserCaptionBackgroundDrawable : mCaptionBackgroundDrawable;

        if (drawable != null) {

            drawable.setBounds(0, 0, left + width, top + mLastCaptionHeight);

            drawable.draw(canvas);

        }

        // The backdrop: clear everything with the background. Clipping is done elsewhere.

        if (mResizingBackgroundDrawable != null) {

            mResizingBackgroundDrawable.setBounds(0, mLastCaptionHeight, left + width, top + height);

            mResizingBackgroundDrawable.draw(canvas);

        }

        mFrameAndBackdropNode.end(canvas);

        if (mSystemBarBackgroundNode != null && mStatusBarColor != null) {