Add cache related metrics for real time URL check.

Metrics added in this CL:
1. SafeBrowsing.RT.HasValidCacheManager
This metrics is for checking if cache manager is valid when real time
url check is enabled.
2. SafeBrowsing.RT.GetCacheResult
This metrics is useful to identify the cache hit rate and the proportion
between safe verdicts and dangerous verdicts.
3. SafeBrowsing.RT.GetCache.Time
This metrics is useful to identify if the time to get cache is too long
compared with its effectiveness.

Bug: 1030989
Change-Id: I616ac3ad3bc207c907bd401801a09a9e46742818
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1974843
Commit-Queue: Xinghui Lu <xinghuilu@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Varun Khaneja <vakh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726621}

components/safe_browsing/browser/safe_browsing_url_checker_impl.cc

@@ -5,6 +5,7 @@
 #include "components/safe_browsing/browser/safe_browsing_url_checker_impl.h"
 
 #include "base/bind.h"
+#include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/histogram_macros_local.h"
 #include "base/task/post_task.h"
@@ -452,20 +453,24 @@ void SafeBrowsingUrlCheckerImpl::OnCheckUrlForHighConfidenceAllowlist(
       FROM_HERE, {content::BrowserThread::UI},
       base::BindOnce(
           &SafeBrowsingUrlCheckerImpl::StartGetCachedRealTimeUrlVerdictOnUI,
-          weak_factory_.GetWeakPtr(), cache_manager_on_ui_, url));
+          weak_factory_.GetWeakPtr(), cache_manager_on_ui_, url,
+          base::TimeTicks::Now()));
 }
 
 // static
 void SafeBrowsingUrlCheckerImpl::StartGetCachedRealTimeUrlVerdictOnUI(
     base::WeakPtr<SafeBrowsingUrlCheckerImpl> weak_checker_on_io,
     base::WeakPtr<VerdictCacheManager> cache_manager_on_ui,
-    const GURL& url) {
+    const GURL& url,
+    base::TimeTicks get_cache_start_time) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   std::unique_ptr<RTLookupResponse::ThreatInfo> cached_threat_info =
       std::make_unique<RTLookupResponse::ThreatInfo>();
-  // TODO(crbug.com/1030989): Add metrics for the proportion of cache_manager
-  // not valid.
+
+  base::UmaHistogramBoolean("SafeBrowsing.RT.HasValidCacheManager",
+                            !!cache_manager_on_ui);
+
   RTLookupResponse::ThreatInfo::VerdictType verdict_type =
       cache_manager_on_ui
           ? cache_manager_on_ui->GetCachedRealTimeUrlVerdict(
@@ -475,17 +480,21 @@ void SafeBrowsingUrlCheckerImpl::StartGetCachedRealTimeUrlVerdictOnUI(
       FROM_HERE, {content::BrowserThread::IO},
       base::BindOnce(
           &SafeBrowsingUrlCheckerImpl::OnGetCachedRealTimeUrlVerdictDoneOnIO,
-          weak_checker_on_io, verdict_type, std::move(cached_threat_info),
-          url));
+          weak_checker_on_io, verdict_type, std::move(cached_threat_info), url,
+          get_cache_start_time));
 }
 
 void SafeBrowsingUrlCheckerImpl::OnGetCachedRealTimeUrlVerdictDoneOnIO(
     RTLookupResponse::ThreatInfo::VerdictType verdict_type,
     std::unique_ptr<RTLookupResponse::ThreatInfo> cached_threat_info,
-    const GURL& url) {
+    const GURL& url,
+    base::TimeTicks get_cache_start_time) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
 
-  // TODO(crbug.com/1030989): Add metrics for cache hit rate and latency.
+  base::UmaHistogramSparse("SafeBrowsing.RT.GetCacheResult", verdict_type);
+  UMA_HISTOGRAM_TIMES("SafeBrowsing.RT.GetCache.Time",
+                      base::TimeTicks::Now() - get_cache_start_time);
+
   if (verdict_type == RTLookupResponse::ThreatInfo::SAFE) {
     OnUrlResult(url, SB_THREAT_TYPE_SAFE, ThreatMetadata());
     return;

components/safe_browsing/browser/safe_browsing_url_checker_impl.h

@@ -126,13 +126,15 @@ class SafeBrowsingUrlCheckerImpl : public mojom::SafeBrowsingUrlChecker,
   static void StartGetCachedRealTimeUrlVerdictOnUI(
       base::WeakPtr<SafeBrowsingUrlCheckerImpl> weak_checker_on_io,
       base::WeakPtr<VerdictCacheManager> cache_manager_on_ui,
-      const GURL& url);
+      const GURL& url,
+      base::TimeTicks get_cache_start_time);
 
   // This function will start real time url lookup if there is no cache match.
   void OnGetCachedRealTimeUrlVerdictDoneOnIO(
       RTLookupResponse::ThreatInfo::VerdictType verdict_type,
       std::unique_ptr<RTLookupResponse::ThreatInfo> cached_threat_info,
-      const GURL& url);
+      const GURL& url,
+      base::TimeTicks get_cache_start_time);
 
   void OnTimeout();
 

tools/metrics/histograms/enums.xml

@@ -55325,6 +55325,12 @@ Called by update_net_trust_anchors.py.-->
   <int value="2" label="BLACKLISTED"/>
 </enum>
 
+<enum name="SafeBrowsingRTLookupResponseVerdictType">
+  <int value="0" label="VERDICT_TYPE_UNSPECIFIED"/>
+  <int value="1" label="SAFE"/>
+  <int value="100" label="DANGEROUS"/>
+</enum>
+
 <enum name="SafeBrowsingStoreAvailabilityResult">
   <int value="0" label="Unknown"/>
   <int value="1" label="Not Enabled"/>

tools/metrics/histograms/histograms.xml

@@ -128093,6 +128093,40 @@ uploading your change for review.
   </summary>
 </histogram>
 
+<histogram name="SafeBrowsing.RT.GetCache.Time" units="ms"
+    expires_after="2020-12-18">
+  <owner>xinghuilu@chromium.org</owner>
+  <owner>chrome-safebrowsing-alerts@google.com</owner>
+  <summary>
+    Logs the latency between the start of getting a result from the cache and
+    when the cache is actually obtained. The time includes bouncing between IO
+    and UI threads. This is an indicator of the efficiency of loading the cache.
+  </summary>
+</histogram>
+
+<histogram name="SafeBrowsing.RT.GetCacheResult"
+    enum="SafeBrowsingRTLookupResponseVerdictType" expires_after="2020-12-18">
+  <owner>xinghuilu@chromium.org</owner>
+  <owner>chrome-safebrowsing-alerts@google.com</owner>
+  <summary>
+    Logs the result of real time URL cache lookup. If the result is
+    VERDICT_TYPE_UNSPECIFIED, that means cache miss and a ping will be sent
+    afterwards. Otherwise, ping won't be sent. This is an indicator of cache hit
+    rate.
+  </summary>
+</histogram>
+
+<histogram name="SafeBrowsing.RT.HasValidCacheManager" enum="BooleanValid"
+    expires_after="2020-12-18">
+  <owner>xinghuilu@chromium.org</owner>
+  <owner>chrome-safebrowsing-alerts@google.com</owner>
+  <summary>
+    Logs if cache manager is valid when real time URL check is enabled. Logged
+    each time if the URL doesn't match the high confidence allowlist. Ideally,
+    cache manager should be valid whenever real time URL check is enabled.
+  </summary>
+</histogram>
+
 <histogram name="SafeBrowsing.RT.LocalMatch.Result"
     enum="SafeBrowsingAllowlistAsyncMatch" expires_after="2020-08-05">
   <owner>vakh@chromium.org</owner>