Revert 182991

tools/telemetry/telemetry/page/scrolling_action.js

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// This file provides the ScrollingAction object, which scrolls a page
-// from top to bottom:
-//   1. var action = new __ScrollingAction(callback)
-//   2. action.start(element_to_scroll)
-'use strict';
-
-(function() {
-  var MAX_SCROLL_LENGTH_PIXELS = 5000;
-
-  var getTimeMs = (function() {
-    if (window.performance)
-      return (performance.now       ||
-              performance.mozNow    ||
-              performance.msNow     ||
-              performance.oNow      ||
-              performance.webkitNow).bind(window.performance);
-    else
-      return function() { return new Date().getTime(); };
-  })();
-
-  var requestAnimationFrame = (function() {
-    return window.requestAnimationFrame       ||
-           window.webkitRequestAnimationFrame ||
-           window.mozRequestAnimationFrame    ||
-           window.oRequestAnimationFrame      ||
-           window.msRequestAnimationFrame     ||
-           function(callback) {
-             window.setTimeout(callback, 1000 / 60);
-           };
-  })().bind(window);
-
-  /**
-   * Scrolls a given element down a certain amount to emulate user scrolling.
-   * Uses smooth scrolling capabilities provided by the platform, if available.
-   * @constructor
-   */
-  function SmoothScrollDownGesture(opt_element) {
-    this.element_ = opt_element || document.body;
-  };
-
-  function min(a, b) {
-    if (a > b) {
-      return b;
-    }
-    return a;
-  };
-
-  function getBoundingVisibleRect(el) {
-    var bound = el.getBoundingClientRect();
-    var rect = { top: bound.top,
-                 left: bound.left,
-                 width: bound.width,
-                 height: bound.height };
-    var outsideHeight = (rect.top + rect.height) - window.innerHeight;
-    var outsideWidth = (rect.left + rect.width) - window.innerWidth;
-
-    if (outsideHeight > 0) {
-      rect.height -= outsideHeight;
-    }
-    if (outsideWidth > 0) {
-      rect.width -= outsideWidth;
-    }
-    return rect;
-  };
-
-  SmoothScrollDownGesture.prototype.start = function(distance, callback) {
-    this.callback_ = callback;
-    if (window.chrome &&
-        chrome.gpuBenchmarking &&
-        chrome.gpuBenchmarking.smoothScrollBy) {
-      var rect = getBoundingVisibleRect(this.element_);
-      chrome.gpuBenchmarking.smoothScrollBy(distance, function() {
-        callback();
-      }, rect.left + rect.width / 2, rect.top + rect.height / 2);
-      return;
-    }
-
-    var SCROLL_DELTA = 100;
-    this.element_.scrollTop += SCROLL_DELTA;
-    requestAnimationFrame(callback);
-  };
-
-  // This class scrolls a page from the top to the bottom once.
-  //
-  // The page is scrolled down by a set of scroll gestures. These gestures
-  // correspond to a reading gesture on that platform.
-  //
-  // start -> startPass_ -> ...scrolling... -> onGestureComplete_ ->
-  //       -> startPass_ -> .. scrolling... -> onGestureComplete_ -> callback_
-  function ScrollingAction(opt_callback) {
-    var self = this;
-
-    this.beginMeasuringHook = function() {}
-    this.endMeasuringHook = function() {}
-
-    this.callback_ = opt_callback;
-  }
-
-  ScrollingAction.prototype.getRemainingScrollDistance_ = function() {
-    var clientHeight;
-    // clientHeight is "special" for the body element.
-    if (this.element_ == document.body)
-      clientHeight = window.innerHeight;
-    else
-      clientHeight = this.element_.clientHeight;
-
-    return this.scrollHeight_ - this.element_.scrollTop - clientHeight;
-  }
-
-  ScrollingAction.prototype.start = function(opt_element) {
-    // Assign this.element_ here instead of constructor, because the constructor
-    // ensures this method will be called after the document is loaded.
-    this.element_ = opt_element || document.body;
-    // Some pages load more content when you scroll to the bottom. Record
-    // the original element height here and only scroll to that point.
-    // -1 to allow for rounding errors on scaled viewports (like mobile).
-    this.scrollHeight_ = Math.min(MAX_SCROLL_LENGTH_PIXELS,
-                                  this.element_.scrollHeight - 1);
-    requestAnimationFrame(this.startPass_.bind(this));
-  };
-
-  ScrollingAction.prototype.startPass_ = function() {
-    this.element_.scrollTop = 0;
-
-    this.beginMeasuringHook();
-
-    this.gesture_ = new SmoothScrollDownGesture(this.element_);
-    this.gesture_.start(this.getRemainingScrollDistance_(),
-                        this.onGestureComplete_.bind(this));
-  };
-
-  ScrollingAction.prototype.getResults = function() {
-    return this.renderingStats_;
-  }
-
-  ScrollingAction.prototype.onGestureComplete_ = function(timestamp) {
-    // If the scrollHeight went down, only scroll to the new scrollHeight.
-    // -1 to allow for rounding errors on scaled viewports (like mobile).
-    this.scrollHeight_ = Math.min(this.scrollHeight_,
-                                  this.element_.scrollHeight - 1);
-
-    if (this.getRemainingScrollDistance_() > 0) {
-      this.gesture_.start(this.getRemainingScrollDistance_(),
-                          this.onGestureComplete_.bind(this));
-      return;
-    }
-
-    this.endMeasuringHook();
-
-    // We're done.
-    if (this.callback_)
-      this.callback_();
-  };
-
-  window.__ScrollingAction = ScrollingAction;
-  window.__ScrollingAction_GetBoundingVisibleRect = getBoundingVisibleRect;
-})();