Report user actions when gesture starts and stops in user_model.

components/scheduler/renderer/user_model_unittest.cc

 // 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"
 
 #include "base/test/simple_test_tick_clock.h"
+#include "base/test/test_simple_task_runner.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace scheduler {
 
 class UserModelTest : public testing::Test {
  public:
-  UserModelTest() {}
+  UserModelTest() : mock_task_runner_(new base::TestSimpleTaskRunner()) {}
   ~UserModelTest() override {}
 
   void SetUp() override {
     clock_.reset(new base::SimpleTestTickClock());
     clock_->Advance(base::TimeDelta::FromMicroseconds(5000));
 
-    user_model_.reset(new UserModel());
+    user_model_.reset(new UserModel(mock_task_runner_));
   }
 
  protected:
   static base::TimeDelta priority_escalation_after_input_duration() {
     return base::TimeDelta::FromMilliseconds(
         UserModel::kGestureEstimationLimitMillis);
   }
 
   static base::TimeDelta subsequent_input_expected_after_input_duration() {
     return base::TimeDelta::FromMilliseconds(
         UserModel::kExpectSubsequentGestureMillis);
   }
 
   scoped_ptr<base::SimpleTestTickClock> clock_;
   scoped_ptr<UserModel> user_model_;
+  scoped_refptr<base::TestSimpleTaskRunner> mock_task_runner_;
 };
 
 TEST_F(UserModelTest, TimeLeftInUserGesture_NoInput) {
   EXPECT_EQ(base::TimeDelta(),
             user_model_->TimeLeftInUserGesture(clock_->NowTicks()));
 }
 
 TEST_F(UserModelTest, TimeLeftInUserGesture_ImmediatelyAfterInput) {
   user_model_->DidStartProcessingInputEvent(
       blink::WebInputEvent::Type::TouchStart, clock_->NowTicks());
@@ skipping 196 matching lines @@
   base::TimeDelta delta(base::TimeDelta::FromMilliseconds(
       UserModel::kMedianGestureDurationMillis * 2));
   clock_->Advance(delta);
 
   base::TimeDelta prediction_valid_duration;
   EXPECT_FALSE(user_model_->IsGestureExpectedToContinue(
       clock_->NowTicks(), &prediction_valid_duration));
   EXPECT_EQ(base::TimeDelta(), prediction_valid_duration);
 }
 
 }  // namespace scheduler

[alex clarke (OOO till 29th), 2016/02/12 16:21:50]

Consider adding a simple test which uses base::AddActionCallback() to check we
get the expected callbacks.

[beaudoin, 2016/03/16 20:47:39]

Done.