Add histogram for whether a model was available at registration

Bug: 1279614
Change-Id: I71982787905cbf263e7322697be65f6f6e3692a2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3490655
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Sophie Chang <sophiechang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#975857}

components/optimization_guide/core/prediction_manager.cc

@@ -189,6 +189,16 @@ bool IsModelMetadataTypeOnServerAllowlist(
              "WebPermissionPredictionsModelMetadata";
 }
 
+void RecordModelAvailableAtRegistration(
+    optimization_guide::proto::OptimizationTarget optimization_target,
+    bool model_available_at_registration) {
+  base::UmaHistogramBoolean(
+      "OptimizationGuide.PredictionManager.ModelAvailableAtRegistration." +
+          optimization_guide::GetStringNameForOptimizationTarget(
+              optimization_target),
+      model_available_at_registration);
+}
+
 }  // namespace
 
 namespace optimization_guide {
@@ -664,6 +674,8 @@ void PredictionManager::LoadPredictionModels(
           BuildPredictionModelFromCommandLineForOptimizationTarget(
               optimization_target);
       OnLoadPredictionModel(std::move(prediction_model));
+      RecordModelAvailableAtRegistration(optimization_target,
+                                         prediction_model != nullptr);
     }
     return;
   }
@@ -675,8 +687,12 @@ void PredictionManager::LoadPredictionModels(
   for (const auto& optimization_target : optimization_targets) {
     // The prediction model for this optimization target has already been
     // loaded.
-    if (!model_and_features_store_->FindPredictionModelEntryKey(
-            optimization_target, &model_entry_key)) {
+    bool model_stored_locally =
+        model_and_features_store_->FindPredictionModelEntryKey(
+            optimization_target, &model_entry_key);
+    RecordModelAvailableAtRegistration(optimization_target,
+                                       model_stored_locally);
+    if (!model_stored_locally) {
       continue;
     }
     model_and_features_store_->LoadPredictionModel(

components/optimization_guide/core/prediction_manager_unittest.cc

@@ -562,6 +562,11 @@ TEST_F(PredictionManagerTest, AddObserverForOptimizationTargetModel) {
   SetStoreInitialized(/* load_models= */ false,
                       /* have_models_in_store= */ false);
 
+  histogram_tester.ExpectUniqueSample(
+      "OptimizationGuide.PredictionManager.ModelAvailableAtRegistration."
+      "PainfulPageLoad",
+      false, 1);
+
   EXPECT_TRUE(prediction_model_fetcher()->models_fetched());
   // Make sure the test histogram is recorded. We don't check for value here
   // since that is too much toil for someone whenever they add a new version.
@@ -589,21 +594,31 @@ TEST_F(PredictionManagerTest, AddObserverForOptimizationTargetModel) {
   model_info.add_additional_files()->set_file_path("");
 
   // Ensure observer is hooked up.
-  proto::PredictionModel model1;
-  *model1.mutable_model_info() = model_info;
-  model1.mutable_model()->set_download_url(
-      FilePathToString(temp_dir().AppendASCII("whatever")));
-  prediction_manager()->OnModelReady(model1);
-  RunUntilIdle();
+  {
+    base::HistogramTester model_ready_histogram_tester;
 
-  absl::optional<ModelInfo> received_model =
-      observer.last_received_model_for_target(
-          proto::OPTIMIZATION_TARGET_PAINFUL_PAGE_LOAD);
-  EXPECT_EQ(received_model->GetModelMetadata()->type_url(), "sometypeurl");
-  EXPECT_EQ(received_model->GetModelFilePath().BaseName().value(),
-            FILE_PATH_LITERAL("whatever"));
-  EXPECT_EQ(received_model->GetAdditionalFiles(),
-            base::flat_set<base::FilePath>{additional_file_path});
+    proto::PredictionModel model1;
+    *model1.mutable_model_info() = model_info;
+    model1.mutable_model()->set_download_url(
+        FilePathToString(temp_dir().AppendASCII("whatever")));
+    prediction_manager()->OnModelReady(model1);
+    RunUntilIdle();
+
+    absl::optional<ModelInfo> received_model =
+        observer.last_received_model_for_target(
+            proto::OPTIMIZATION_TARGET_PAINFUL_PAGE_LOAD);
+    EXPECT_EQ(received_model->GetModelMetadata()->type_url(), "sometypeurl");
+    EXPECT_EQ(received_model->GetModelFilePath().BaseName().value(),
+              FILE_PATH_LITERAL("whatever"));
+    EXPECT_EQ(received_model->GetAdditionalFiles(),
+              base::flat_set<base::FilePath>{additional_file_path});
+
+    // Make sure we do not record the model available histogram again.
+    model_ready_histogram_tester.ExpectTotalCount(
+        "OptimizationGuide.PredictionManager.ModelAvailableAtRegistration."
+        "PainfulPageLoad",
+        0);
+  }
 
   // Reset fetcher and make sure version is sent in the new request and not
   // counted as re-loaded or updated.
@@ -780,9 +795,15 @@ TEST_F(PredictionManagerTest,
   base::HistogramTester histogram_tester;
 
   CreatePredictionManager();
+  SetStoreInitialized(/*load_models=*/false, /*have_models_in_store=*/false);
   FakeOptimizationTargetModelObserver observer;
   prediction_manager()->AddObserverForOptimizationTargetModel(
-      proto::OPTIMIZATION_TARGET_PAINFUL_PAGE_LOAD, absl::nullopt, &observer);
+      proto::OPTIMIZATION_TARGET_MODEL_VALIDATION, absl::nullopt, &observer);
+
+  histogram_tester.ExpectUniqueSample(
+      "OptimizationGuide.PredictionManager.ModelAvailableAtRegistration."
+      "ModelValidation",
+      false, 1);
 }
 
 TEST_F(PredictionManagerTest, UpdatePredictionModelsWithInvalidModel) {
@@ -931,6 +952,16 @@ TEST_F(PredictionManagerTest, UpdateModelForUnregisteredTargetOnModelReady) {
 
   histogram_tester.ExpectTotalCount(
       "OptimizationGuide.PredictionModelLoadedVersion.PainfulPageLoad", 0);
+
+  // Now register the model.
+  FakeOptimizationTargetModelObserver observer;
+  prediction_manager()->AddObserverForOptimizationTargetModel(
+      proto::OPTIMIZATION_TARGET_PAINFUL_PAGE_LOAD, absl::nullopt, &observer);
+
+  histogram_tester.ExpectUniqueSample(
+      "OptimizationGuide.PredictionManager.ModelAvailableAtRegistration."
+      "PainfulPageLoad",
+      true, 1);
 }
 
 TEST_F(PredictionManagerTest,
@@ -952,6 +983,10 @@ TEST_F(PredictionManagerTest,
   EXPECT_FALSE(prediction_model_fetcher()->models_fetched());
   histogram_tester.ExpectUniqueSample(
       "OptimizationGuide.PredictionModelLoadedVersion.PainfulPageLoad", 1, 1);
+  histogram_tester.ExpectUniqueSample(
+      "OptimizationGuide.PredictionManager.ModelAvailableAtRegistration."
+      "PainfulPageLoad",
+      true, 1);
 }
 
 TEST_F(PredictionManagerTest,
@@ -975,6 +1010,10 @@ TEST_F(PredictionManagerTest,
   EXPECT_FALSE(prediction_model_fetcher()->models_fetched());
   histogram_tester.ExpectUniqueSample(
       "OptimizationGuide.PredictionModelLoadedVersion.PainfulPageLoad", 1, 1);
+  histogram_tester.ExpectUniqueSample(
+      "OptimizationGuide.PredictionManager.ModelAvailableAtRegistration."
+      "PainfulPageLoad",
+      true, 1);
 }
 
 TEST_F(PredictionManagerTest, ModelFetcherTimerRetryDelay) {

tools/metrics/histograms/metadata/optimization/histograms.xml

@@ -823,6 +823,20 @@ chromium-metrics-reviews@google.com.
   <token key="OptimizationTarget" variants="OptimizationTarget"/>
 </histogram>
 
+<histogram base="true"
+    name="OptimizationGuide.PredictionManager.ModelAvailableAtRegistration.{OptimizationTarget}"
+    units="BooleanAvailable" expires_after="M106">
+  <owner>sophiechang@chromium.org</owner>
+  <owner>mcrouse@chromium.org</owner>
+  <summary>
+    Records whether the model was in the local store for {OptimizationTarget}
+    when the observer for {OptimizationTarget} was registered with the
+    prediction manager. Recorded at most once per session (profile start) when
+    {OptimizationTarget} is registered.
+  </summary>
+  <token key="OptimizationTarget" variants="OptimizationTarget"/>
+</histogram>
+
 <histogram base="true"
     name="OptimizationGuide.PredictionManager.ModelTypeChanged.{OptimizationTarget}"
     units="BooleanChanged" expires_after="M106">