Turn on UKM NavigationPredictor metrics collection.

Change-Id: I76b80b77cf72e91d83b89a002c598e8447f9f1e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1723307Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Commit-Queue: Sofiya Semenova <sofiyase@google.com>
Cr-Commit-Position: refs/heads/master@{#682369}

chrome/browser/navigation_predictor/navigation_predictor.cc

@@ -219,11 +219,7 @@ NavigationPredictor::NavigationPredictor(
       normalize_navigation_scores_(base::GetFieldTrialParamByFeatureAsBool(
           blink::features::kNavigationPredictor,
           "normalize_scores",
-          true)),
-      send_ukm_metrics_(base::GetFieldTrialParamByFeatureAsBool(
-          blink::features::kNavigationPredictor,
-          "send_ukm_metrics",
-          false)) {
+          true)) {
   DCHECK(browser_context_);
   DETACH_FROM_SEQUENCE(sequence_checker_);
   DCHECK_LE(0, preconnect_origin_score_threshold_);
@@ -440,7 +436,7 @@ void NavigationPredictor::MaybePreconnectNow(Action log_action) {
 }
 
 void NavigationPredictor::MaybeSendMetricsToUkm() const {
-  if (!send_ukm_metrics_ || !ukm_recorder_) {
+  if (!ukm_recorder_) {
     return;
   }
 
@@ -513,7 +509,7 @@ int NavigationPredictor::GetLinearBucketForRatioArea(int value) const {
 
 void NavigationPredictor::MaybeSendClickMetricsToUkm(
     const std::string& clicked_url) const {
-  if (!send_ukm_metrics_ || !ukm_recorder_) {
+  if (!ukm_recorder_) {
     return;
   }
 

chrome/browser/navigation_predictor/navigation_predictor.h

@@ -196,14 +196,13 @@ class NavigationPredictor : public blink::mojom::AnchorElementMetricsHost,
   // MaybePreconnectNow preconnects to an origin server if it's allowed.
   void MaybePreconnectNow(Action log_action);
 
-  // Sends metrics to the UKM id at |ukm_source_id_| if |send_ukm_metrics_|
-  // is true.
+  // Sends metrics to the UKM id at |ukm_source_id_|.
   void MaybeSendMetricsToUkm() const;
 
   // After an in-page click, sends the index of the url that was clicked to the
-  // UKM id at |ukm_source_id_| if |send_ukm_metrics_| is true. The index sent
-  // corresponds to the index of that url in |top_urls_|, and is 1-indexed.
-  // If the url does not appear in top_urls_, a 0 is returned.
+  // UKM id at |ukm_source_id_|. The index sent corresponds to the index of that
+  // url in |top_urls_|, and is 1-indexed. If the url does not appear in
+  // |top_urls_|, a 0 is returned.
   void MaybeSendClickMetricsToUkm(const std::string& clicked_url) const;
 
   // Returns the minimum of the bucket that |value| belongs in, for page-wide
@@ -299,10 +298,6 @@ class NavigationPredictor : public blink::mojom::AnchorElementMetricsHost,
   // all navigation scores for a page.
   const bool normalize_navigation_scores_;
 
-  // True if |this| should send metrics about aggregate link information
-  // to the UKM at id |ukm_source_id_|.
-  const bool send_ukm_metrics_;
-
   // Timing of document loaded and last click.
   base::TimeTicks document_loaded_timing_;
   base::TimeTicks last_click_timing_;

chrome/browser/navigation_predictor/navigation_predictor_unittest.cc

@@ -128,8 +128,7 @@ class NavigationPredictorTest : public ChromeRenderViewHostTestHarness {
 
   void SetupFieldTrial(base::Optional<int> preconnect_origin_score_threshold,
                        base::Optional<int> prefetch_url_score_threshold,
-                       base::Optional<bool> prefetch_after_preconnect,
-                       base::Optional<bool> send_ukm_metrics) {
+                       base::Optional<bool> prefetch_after_preconnect) {
     if (field_trial_initiated_)
       return;
 
@@ -150,9 +149,6 @@ class NavigationPredictorTest : public ChromeRenderViewHostTestHarness {
       params["prefetch_after_preconnect"] =
           prefetch_after_preconnect.value() ? "true" : "false";
     }
-    if (send_ukm_metrics.has_value()) {
-      params["send_ukm_metrics"] = send_ukm_metrics.value() ? "true" : "false";
-    }
     scoped_feature_list.InitAndEnableFeatureWithParameters(
         blink::features::kNavigationPredictor, params);
   }
@@ -504,7 +500,7 @@ class NavigationPredictorSendUkmMetricsEnabledTest
     : public NavigationPredictorTest {
  public:
   NavigationPredictorSendUkmMetricsEnabledTest() {
-    SetupFieldTrial(base::nullopt, base::nullopt, base::nullopt, true);
+    SetupFieldTrial(base::nullopt, base::nullopt, base::nullopt);
   }
 
   void SetUp() override {
@@ -721,7 +717,7 @@ class NavigationPredictorPrefetchAfterPreconnectEnabledTest
     : public NavigationPredictorTest {
  public:
   NavigationPredictorPrefetchAfterPreconnectEnabledTest() {
-    SetupFieldTrial(base::nullopt, base::nullopt, true, base::nullopt);
+    SetupFieldTrial(base::nullopt, base::nullopt, true);
   }
 
   void SetUp() override {
@@ -768,8 +764,7 @@ class NavigationPredictorPrefetchDisabledTest : public NavigationPredictorTest {
  public:
   NavigationPredictorPrefetchDisabledTest() {
     SetupFieldTrial(0 /* preconnect_origin_score_threshold */,
-                    101 /* prefetch_url_score_threshold */, base::nullopt,
-                    base::nullopt);
+                    101 /* prefetch_url_score_threshold */, base::nullopt);
   }
 
   void SetUp() override {
@@ -867,8 +862,7 @@ class NavigationPredictorPreconnectPrefetchDisabledTest
  public:
   NavigationPredictorPreconnectPrefetchDisabledTest() {
     SetupFieldTrial(101 /* preconnect_origin_score_threshold */,
-                    101 /* prefetch_url_score_threshold */, base::nullopt,
-                    base::nullopt);
+                    101 /* prefetch_url_score_threshold */, base::nullopt);
   }
 
   void SetUp() override {