Instrument BackgroundFetchRegistration for the identifiability study.

Bug: 973801
Change-Id: Ia2095b57b5d23f429a33cd99c00d0e90054082b3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2438480Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Caleb Raitto <caraitto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#812196}

third_party/blink/public/mojom/web_feature/web_feature.mojom

@@ -2824,7 +2824,7 @@ enum WebFeature {
   kIdentifiabilityStudyReserved3496 = 3496,
   kIdentifiabilityStudyReserved3497 = 3497,
   kIdentifiabilityStudyReserved3498 = 3498,
-  kIdentifiabilityStudyReserved3499 = 3499,
+  kV8BackgroundFetchRegistration_FailureReason_AttributeGetter = 3499,
   kIdentifiabilityStudyReserved3500 = 3500,
   kIdentifiabilityStudyReserved3501 = 3501,
   kIdentifiabilityStudyReserved3502 = 3502,

third_party/blink/renderer/modules/background_fetch/background_fetch_registration.cc

@@ -8,6 +8,8 @@
 
 #include "base/metrics/histogram_macros.h"
 #include "base/optional.h"
+#include "third_party/blink/public/common/privacy_budget/identifiability_metric_builder.h"
+#include "third_party/blink/public/common/privacy_budget/identifiable_surface.h"
 #include "third_party/blink/public/mojom/fetch/fetch_api_request.mojom-blink.h"
 #include "third_party/blink/renderer/bindings/modules/v8/v8_cache_query_options.h"
 #include "third_party/blink/renderer/bindings/modules/v8/v8_image_resource.h"
@@ -336,6 +338,15 @@ const String BackgroundFetchRegistration::result() const {
 }
 
 const String BackgroundFetchRegistration::failureReason() const {
+  blink::IdentifiabilityMetricBuilder(GetExecutionContext()->UkmSourceID())
+      .Set(
+          blink::IdentifiableSurface::FromTypeAndToken(
+              blink::IdentifiableSurface::Type::kWebFeature,
+              WebFeature::
+                  kV8BackgroundFetchRegistration_FailureReason_AttributeGetter),
+          failure_reason_ ==
+              mojom::BackgroundFetchFailureReason::QUOTA_EXCEEDED)
+      .Record(GetExecutionContext()->UkmRecorder());
   switch (failure_reason_) {
     case mojom::BackgroundFetchFailureReason::NONE:
       return "";

third_party/blink/renderer/modules/background_fetch/background_fetch_registration.idl

@@ -14,7 +14,7 @@
     readonly attribute unsigned long long downloadTotal;
     readonly attribute unsigned long long downloaded;
     readonly attribute BackgroundFetchResult result;
-    readonly attribute BackgroundFetchFailureReason failureReason;
+    [HighEntropy, Measure] readonly attribute BackgroundFetchFailureReason failureReason;
     readonly attribute boolean recordsAvailable;
 
     attribute EventHandler onprogress;

tools/metrics/histograms/enums.xml

@@ -29289,7 +29289,8 @@ Called by update_use_counter_feature_enum.py.-->
   <int value="3496" label="IdentifiabilityStudyReserved3496"/>
   <int value="3497" label="IdentifiabilityStudyReserved3497"/>
   <int value="3498" label="IdentifiabilityStudyReserved3498"/>
-  <int value="3499" label="IdentifiabilityStudyReserved3499"/>
+  <int value="3499"
+      label="V8BackgroundFetchRegistration_FailureReason_AttributeGetter"/>
   <int value="3500" label="IdentifiabilityStudyReserved3500"/>
   <int value="3501" label="IdentifiabilityStudyReserved3501"/>
   <int value="3502" label="IdentifiabilityStudyReserved3502"/>