Merge "HWUI: do not call glCopyTexSubImage2D on empty area." into nyc-dev

}

OffscreenBuffer* BakedOpRenderer::copyToLayer(const Rect& area) {

    OffscreenBuffer* buffer = mRenderState.layerPool().get(mRenderState,

            area.getWidth(), area.getHeight());

    if (!area.isEmpty()) {

    const uint32_t width = area.getWidth();

    const uint32_t height = area.getHeight();

    OffscreenBuffer* buffer = mRenderState.layerPool().get(mRenderState, width, height);

    if (!area.isEmpty() && width != 0 && height != 0) {

        mCaches.textureState().activateTexture(0);

        mCaches.textureState().bindTexture(buffer->texture.id());

        glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0,

                area.left, mRenderTarget.viewportHeight - area.bottom,

                area.getWidth(), area.getHeight());

                area.left, mRenderTarget.viewportHeight - area.bottom, width, height);

    }

    return buffer;

}