Revert of Optimize for TouchStart responsiveness

components/scheduler/renderer/user_model.cc

Index: components/scheduler/renderer/user_model.cc
diff --git a/components/scheduler/renderer/user_model.cc b/components/scheduler/renderer/user_model.cc
deleted file mode 100644
index 81abada59856e856c73e5ba3a537fcddc128ceb7..0000000000000000000000000000000000000000
--- a/components/scheduler/renderer/user_model.cc
+++ /dev/null
@@ -1,110 +0,0 @@
-// Copyright 2015 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.
-
-#include "components/scheduler/renderer/user_model.h"
-
-namespace scheduler {
-
-UserModel::UserModel() : pending_input_event_count_(0) {}
-UserModel::~UserModel() {}
-
-void UserModel::DidStartProcessingInputEvent(blink::WebInputEvent::Type type,
-                                             const base::TimeTicks now) {
-  last_input_signal_time_ = now;
-  if (type == blink::WebInputEvent::TouchStart ||
-      type == blink::WebInputEvent::GestureScrollBegin ||
-      type == blink::WebInputEvent::GesturePinchBegin) {
-    last_gesture_start_time_ = now;
-  }
-
-  // We need to track continuous gestures seperatly for scroll detection
-  // because taps should not be confused with scrolls.
-  if (type == blink::WebInputEvent::GestureScrollBegin ||
-      type == blink::WebInputEvent::GestureScrollEnd ||
-      type == blink::WebInputEvent::GestureScrollUpdate ||
-      type == blink::WebInputEvent::GestureFlingStart ||
-      type == blink::WebInputEvent::GestureFlingCancel ||
-      type == blink::WebInputEvent::GesturePinchBegin ||
-      type == blink::WebInputEvent::GesturePinchEnd ||
-      type == blink::WebInputEvent::GesturePinchUpdate) {
-    last_continuous_gesture_time_ = now;
-  }
-
-  pending_input_event_count_++;
-}
-
-void UserModel::DidFinishProcessingInputEvent(const base::TimeTicks now) {
-  last_input_signal_time_ = now;
-  if (pending_input_event_count_ > 0)
-    pending_input_event_count_--;
-}
-
-base::TimeDelta UserModel::TimeLeftInUserGesture(base::TimeTicks now) const {
-  base::TimeDelta escalated_priority_duration =
-      base::TimeDelta::FromMilliseconds(kGestureEstimationLimitMillis);
-
-  // If the input event is still pending, go into input prioritized policy and
-  // check again later.
-  if (pending_input_event_count_ > 0)
-    return escalated_priority_duration;
-  if (last_input_signal_time_.is_null() ||
-      last_input_signal_time_ + escalated_priority_duration < now) {
-    return base::TimeDelta();
-  }
-  return last_input_signal_time_ + escalated_priority_duration - now;
-}
-
-bool UserModel::IsGestureExpectedSoon(
-    RendererScheduler::UseCase use_case,
-    const base::TimeTicks now,
-    base::TimeDelta* prediction_valid_duration) const {
-  if (use_case == RendererScheduler::UseCase::NONE) {
-    // If we've scrolled recently then future scrolling is likely.
-    base::TimeDelta expect_subsequent_gesture_for =
-        base::TimeDelta::FromMilliseconds(kExpectSubsequentGestureMillis);
-    if (last_continuous_gesture_time_.is_null() ||
-        last_continuous_gesture_time_ + expect_subsequent_gesture_for <= now) {
-      return false;
-    }
-    *prediction_valid_duration =
-        last_continuous_gesture_time_ + expect_subsequent_gesture_for - now;
-    return true;
-  }
-
-  if (use_case == RendererScheduler::UseCase::COMPOSITOR_GESTURE ||
-      use_case == RendererScheduler::UseCase::MAIN_THREAD_GESTURE) {
-    // If we've only just started scrolling then, then initiating a subsequent
-    // gesture is unlikely.
-    base::TimeDelta minimum_typical_scroll_duration =
-        base::TimeDelta::FromMilliseconds(kMinimumTypicalScrollDurationMillis);
-    if (last_gesture_start_time_.is_null() ||
-        last_gesture_start_time_ + minimum_typical_scroll_duration <= now) {
-      return true;
-    }
-    *prediction_valid_duration =
-        last_gesture_start_time_ + minimum_typical_scroll_duration - now;
-    return false;
-  }
-  return false;
-}
-
-void UserModel::Reset() {
-  last_input_signal_time_ = base::TimeTicks();
-  last_gesture_start_time_ = base::TimeTicks();
-  last_continuous_gesture_time_ = base::TimeTicks();
-}
-
-void UserModel::AsValueInto(base::trace_event::TracedValue* state) const {
-  state->BeginDictionary("user_model");
-  state->SetInteger("pending_input_event_count", pending_input_event_count_);
-  state->SetDouble(
-      "last_input_signal_time",
-      (last_input_signal_time_ - base::TimeTicks()).InMillisecondsF());
-  state->SetDouble(
-      "last_touchstart_time",
-      (last_gesture_start_time_ - base::TimeTicks()).InMillisecondsF());
-  state->EndDictionary();
-}
-
-}  // namespace scheduler