Report user actions when gesture starts and stops in user_model.

components/scheduler/renderer/user_model_unittest.cc

Index: components/scheduler/renderer/user_model_unittest.cc
diff --git a/components/scheduler/renderer/user_model_unittest.cc b/components/scheduler/renderer/user_model_unittest.cc
index ebf3ff345c7bbbc282029049de09f4e450d548be..277c0ae6f06b14cfae0f41e9088ea727974a0824 100644
--- a/components/scheduler/renderer/user_model_unittest.cc
+++ b/components/scheduler/renderer/user_model_unittest.cc
@@ -4,7 +4,11 @@
 
 #include "components/scheduler/renderer/user_model.h"
 
+#include "base/metrics/field_trial.h"
+#include "base/metrics/user_metrics.h"
+#include "base/metrics/user_metrics_action.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"
 
@@ -12,14 +16,22 @@ namespace scheduler {
 
 class UserModelTest : public testing::Test {
  public:
-  UserModelTest() {}
-  ~UserModelTest() override {}
+  UserModelTest() : mock_task_runner_(new base::TestSimpleTaskRunner()) {}
+  ~UserModelTest() override { base::RemoveActionCallback(action_callback_); }
 
   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_));
+
+    // Register a mock user action callback for testing.
+    numActionsRecorded_ = 0;
+    lastActionRecorded_ = "";
+    base::RemoveActionCallback(action_callback_);
+    action_callback_ = base::Bind(&UserModelTest::RecordComputedAction,
+                                  base::Unretained(this));
+    base::AddActionCallback(action_callback_);
   }
 
  protected:
@@ -33,8 +45,19 @@ class UserModelTest : public testing::Test {
         UserModel::kExpectSubsequentGestureMillis);
   }
 
+  void RecordComputedAction(const std::string& action) {
+    numActionsRecorded_++;
+    lastActionRecorded_ = action;
+  }
+
   scoped_ptr<base::SimpleTestTickClock> clock_;
   scoped_ptr<UserModel> user_model_;
+  scoped_refptr<base::TestSimpleTaskRunner> mock_task_runner_;
+  base::ActionCallback action_callback_;
+
+  // Tracks user actions that were recorded.
+  int numActionsRecorded_;
+  std::string lastActionRecorded_;
 };
 
 TEST_F(UserModelTest, TimeLeftInUserGesture_NoInput) {
@@ -237,18 +260,32 @@ TEST_F(UserModelTest, IsGestureExpectedToContinue_ShortlyAfterGestureStarted) {
             prediction_valid_duration);
 }
 
-TEST_F(UserModelTest, IsGestureExpectedToContinue_LongAfterGestureStarted) {
+TEST_F(UserModelTest, AreActionsLogged) {
+  // Add the action logging feature.
+  base::FeatureList::ClearInstanceForTesting();
+  scoped_ptr<base::FeatureList> feature_list(new base::FeatureList);
+  feature_list->InitializeFromCommandLine(features::kRecordGestureAction.name,
+                                          "");
+  base::FeatureList::SetInstance(std::move(feature_list));
+
+  EXPECT_EQ(0, numActionsRecorded_);
+
   user_model_->DidStartProcessingInputEvent(
       blink::WebInputEvent::Type::GestureScrollBegin, clock_->NowTicks());
+  mock_task_runner_->RunPendingTasks();
 
-  base::TimeDelta delta(base::TimeDelta::FromMilliseconds(
-      UserModel::kMedianGestureDurationMillis * 2));
+  EXPECT_EQ(1, numActionsRecorded_);
+  EXPECT_EQ("RendererScheduler.UserModel.GestureStart", lastActionRecorded_);
+
+  base::TimeDelta delta(base::TimeDelta::FromMilliseconds(500));
   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);
+  user_model_->DidStartProcessingInputEvent(
+      blink::WebInputEvent::Type::GestureScrollEnd, clock_->NowTicks());
+  mock_task_runner_->RunPendingTasks();
+
+  EXPECT_EQ(2, numActionsRecorded_);
+  EXPECT_EQ("RendererScheduler.UserModel.GestureEnd", lastActionRecorded_);
 }
 
 }  // namespace scheduler