Source: gfx/core/renderers/webgl/managers/WebGLManager.js

/**
 * @class
 * @param renderer {WebGLRenderer} The renderer this manager works for.
 */
function WebGLManager(renderer) {
    /**
     * The renderer this manager works for.
     *
     * @member {WebGLRenderer}
     */
  this.renderer = renderer;

  this.renderer.on('context', this.onContextChange, this);
}

WebGLManager.prototype.constructor = WebGLManager;
module.exports = WebGLManager;

/**
 * Generic method called when there is a WebGL context change.
 *
 */
WebGLManager.prototype.onContextChange = function() {
	// do some codes init!
};

/**
 * Generic destroy methods to be overridden by the subclass
 *
 */
WebGLManager.prototype.destroy = function() {
  this.renderer.off('context', this.onContextChange, this);

  this.renderer = null;
};