Adding support for animated pages in the FrameRate tests

chrome/test/data/perf/frame_rate/head.js

 // Copyright (c) 2011 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.
 
 /**
  * @fileoverview  Perform various "gestures" and calculate average frame rate.
  * "Gestures" are recorded scrolling behaviors in terms of time (ms) and
  * absolute positions.
  *
  * How to run a single gesture:
@@ skipping 16 matching lines @@
  *  5) Copy the output from "JSON.stringify(__recording)" in the console.
  *  6) Paste the output in this file as a new member of __gestures.
  *  7) Copy the formatting from other gestures.
  *    Example:
  *      new_gesture_name: [
  *        {"time_ms":1, "y":0},
  *        ... pasted output ...
  *      ],
  */
 
+var __initialized = true;
 var __running = false;
 var __running_all = false;
 var __old_title = "";
 var __raf_is_live = false;
 var __raf;
 
 var __t_last;
 var __t_est;
 var __t_est_total;
 var __t_est_squared_total;
 var __t_count;
 var __t_start;
 
 var __queued_gesture_functions;
 var __results;
 
 var __recording = [];
 var __advance_gesture;
-var __gestures = {
-  none: [
+
+// This flag indicates whether the test page contains an animation loop
+// For more on testing animated pages, see head_animation.js
+var __animation = false;
+
+var __gesture_library = {
+  init: [
+    {"time_ms":1, "y":0},
+    {"time_ms":5, "y":10}
+  ],
+  stationary: [
     {"time_ms":1, "y":0},
     {"time_ms":5000, "y":0}
   ],
-  steady: [
-    {"time_ms":1, "y":0},
-    {"time_ms":5, "y":10}
-  ],
   reading: [
     {"time_ms":1, "y":0},
     {"time_ms":842, "y":40},
     {"time_ms":858, "y":67},
     {"time_ms":874, "y":94},
     {"time_ms":890, "y":149},
     {"time_ms":907, "y":203},
     {"time_ms":923, "y":257},
     {"time_ms":939, "y":311},
     {"time_ms":955, "y":393},
@@ skipping 80 matching lines @@
     {"time_ms":911, "y":1273},
     {"time_ms":941, "y":1275},
     {"time_ms":958, "y":1282},
     {"time_ms":976, "y":1288},
     {"time_ms":993, "y":1291},
     {"time_ms":1022, "y":1294},
     {"time_ms":1055, "y":1302}
   ],
 };
 
+// Stretch the duration of a gesture by a given factor
+function __gesture_stretch(gesture, stretch_factor) {
+  // clone the gesture
+  var new_gesture = JSON.parse(JSON.stringify(gesture));
+  for (var i = 0; i < new_gesture.length; ++i) {
+    new_gesture[i].time_ms *= stretch_factor;
+  }
+  return new_gesture;
+}
+
+// Gesture set to use for testing, initialized with default gesture set.
+// Redefine in test file to use a different set of gestures.
+var __gestures = {
+  none: __gesture_library["stationary"],
+  steady: __gesture_library["init"],
+  reading: __gesture_library["reading"],
+  mouse_wheel: __gesture_library["mouse_wheel"],
+  mac_fling: __gesture_library["mac_fling"],
+};
+
 function __init_stats() {
   __t_last = undefined;
   __t_est = undefined;
   __t_est_total = 0;
   __t_est_squared_total = 0;
   __t_count = 0;
 }
 __init_stats();
 
+function __init_raf() {
+  if ("requestAnimationFrame" in window)
+    __raf = requestAnimationFrame;
+  else if ("webkitRequestAnimationFrame" in window)
+    __raf = webkitRequestAnimationFrame;
+  else if ("mozRequestAnimationFrame" in window)
+    __raf = mozRequestAnimationFrame;
+  else if ("oRequestAnimationFrame" in window)
+    __raf = oRequestAnimationFrame;
+  else if ("msRequestAnimationFrame" in window)
+    __raf = msRequestAnimationFrame;
+  else
+    // No raf implementation available, fake it with 16ms timeouts
+    __raf = function(callback, element) {
+      setTimeout(callback, 16);
+    }
+}
+__init_raf();
+
 function __calc_results() {
   var M = __t_est_total / __t_count;
   var X = __t_est_squared_total / __t_count;
   var V = X - M * M;
   var S = Math.sqrt(V);
 
   var R = new Object();
   R.mean = 1000.0 / M;
   R.sigma = R.mean - 1000.0 / (M + S);
   return R;
@@ skipping 138 matching lines @@
     y = gestures[i].y + dy;
     gestures.push({
       time_ms: gestures[i].time_ms + dtime_ms,
       y: y,
     });
   }
   return __create_gesture_function(gestures);
 }
 
 function __sched_update() {
-  if (!__raf) {
-    if ("webkitRequestAnimationFrame" in window)
-      __raf = webkitRequestAnimationFrame;
-    else if ("mozRequestAnimationFrame" in window)
-      __raf = mozRequestAnimationFrame;
-  }
   __raf(function() {
     __raf_is_live = true;
+    // In case __raf falls back to using setTimeout, we must schedule the next
+    // update before rendering the current update to help maintain the
+    // regularity of update intervals.
+    __sched_update();
     if (__running) {
       // Only update the FPS if a gesture movement occurs. Otherwise, the frame
       // rate average becomes inaccurate after any pause.
       if (__advance_gesture())
         __update_fps();
       else
         __t_last = new Date().getTime();
     }
-    __sched_update();
   }, document.body);
 }
 
 function __start_recording() {
   __start(__advance_gesture_recording);
 }
 
 function __make_body_composited() {
   document.body.style.webkitTransform = "translateZ(0)";
 }
 
 function __start(gesture_function) {
   if (__running)
     return;
   // Attempt to create a gesture function from a string name.
   if (typeof gesture_function == "string") {
-    if (!__gestures[gesture_function])
-      throw new Error("Unrecognized gesture name");
+    if (!__gestures[gesture_function]) {
+      if (!__gesture_library[gesture_function])
+        throw new Error("Unrecognized gesture name");
+      else
+        gesture_function = __create_repeating_gesture_function(
+                            __gesture_library[gesture_function]);
+    }
     else
       gesture_function = __create_repeating_gesture_function(
                             __gestures[gesture_function]);
   }
   else if (typeof gesture_function != "function")
     throw new Error("Argument is not a function or gesture name");
 
   __old_title = document.title;
   __advance_gesture = gesture_function;
   __t_start = new Date().getTime();
   __running = true;
-  if (!__raf_is_live) {
+  if (!__raf_is_live && !__animation) {
     __sched_update();
   }
 }
 
 function __start_all() {
   __queued_gesture_functions = [];
   __results = {
     gestures: [],
     means: [],
     sigmas: [],
   };
 
   for (var gesture in __gestures) {
     __results.gestures.push(gesture);
     __queued_gesture_functions.push(gesture);
   }
   __running_all = true;
-  // Run steady gesture once to cache the webpage layout for subsequent tests.
-  __start("steady");
+  // Run init gesture once to cache the webpage layout for subsequent tests.
+  __start("init");
 }
 
 function __stop() {
   __running = false;
   document.title = __old_title;
   window.__scrolledTo = undefined;
 
   if (__running_all) {
     var results = __calc_results();
     __results.means.push(results.mean);
@@ skipping 13 matching lines @@
   __running = false;
   __running_all = false;
   document.title = __old_title;
   document.body.scrollTop = 0;
   __init_stats();
 }
 
 function __force_compositor() {
   document.body.style.webkitTransform = "translateZ(0)";
 }