Log CheckDelta when response status is SuccessWithRealTime

Since GMSCore is still rolling out, a lot of real time checks fall
back to local blocklist checks. Add a histogram that logs CheckDelta
only if the response status is SuccessWithRealTime so that we get
a clear picture of the latency of real time check.

Bug: 40911907
Change-Id: I53ee1b2289744a6f40789c28c7a72e6168a571b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5319779
Reviewed-by: thefrog <thefrog@chromium.org>
Commit-Queue: Xinghui Lu <xinghuilu@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1264634}

components/safe_browsing/android/safe_browsing_api_handler_bridge.cc

@@ -124,6 +124,13 @@ void ReportSafeBrowsingJavaResponse(
   ReportUmaHistogramSparseWithAndWithoutSuffix(
       "SafeBrowsing.GmsSafeBrowsingApi.ResponseStatus", suffix,
       static_cast<int>(response_status));
+
+  if (response_status ==
+      SafeBrowsingJavaResponseStatus::SUCCESS_WITH_REAL_TIME) {
+    base::UmaHistogramMicrosecondsTimes(
+        "SafeBrowsing.GmsSafeBrowsingApi.CheckDelta.SuccessWithRealTime",
+        base::Microseconds(check_delta_microseconds));
+  }
 }
 
 SafeBrowsingJavaValidationResult GetJavaValidationResult(

components/safe_browsing/android/safe_browsing_api_handler_bridge_unittest.cc

@@ -294,6 +294,18 @@ class SafeBrowsingApiHandlerBridgeTest : public testing::Test {
           "SafeBrowsing.GmsSafeBrowsingApi.ResponseStatus" + suffix,
           /*sample=*/expected_response_status.value(),
           /*expected_bucket_count=*/1);
+      if (expected_response_status.value() ==
+          static_cast<int>(
+              SafeBrowsingJavaResponseStatus::SUCCESS_WITH_REAL_TIME)) {
+        histogram_tester_.ExpectUniqueSample(
+            "SafeBrowsing.GmsSafeBrowsingApi.CheckDelta.SuccessWithRealTime",
+            /*sample=*/kExpectedSafeBrowsingCheckDeltaMicroseconds,
+            /*expected_bucket_count=*/1);
+      } else {
+        histogram_tester_.ExpectTotalCount(
+            "SafeBrowsing.GmsSafeBrowsingApi.CheckDelta.SuccessWithRealTime",
+            /*expected_count=*/0);
+      }
     } else {
       histogram_tester_.ExpectTotalCount(
           /*name=*/"SafeBrowsing.GmsSafeBrowsingApi.ResponseStatus",

tools/metrics/histograms/metadata/safe_browsing/histograms.xml

@@ -1048,6 +1048,23 @@ chromium-metrics-reviews@google.com.
   </summary>
 </histogram>
 
+<histogram
+    name="SafeBrowsing.GmsSafeBrowsingApi.CheckDelta.SuccessWithRealTime"
+    units="microseconds" expires_after="2024-07-07">
+  <owner>xinghuilu@chromium.org</owner>
+  <owner>chrome-counter-abuse-alerts@google.com</owner>
+  <summary>
+    The microseconds between sending the SafeBrowsing API real time call and
+    receiving the SUCCESS_WITH_REAL_TIME response. The end time is fixed in java
+    code and does not include any thread hops or extra work. Note that this does
+    include task queue time to respond to the IPC (and that queue time is often
+    non-trivial). This is logged each time a SUCCESS_WITH_REAL_TIME response is
+    received from SafeBrowsing API.
+
+    This histogram only records metrics on machines with high-resolution clocks.
+  </summary>
+</histogram>
+
 <histogram name="SafeBrowsing.GmsSafeBrowsingApi.CheckDelta{Protocol}"
     units="microseconds" expires_after="2024-07-07">
   <owner>xinghuilu@chromium.org</owner>