Add some metrics for Client Side Phishing Detection

Based on some recent problems with the Client Side Phishing system, we
could use a few more high-level metrics. This CL adds three such
metrics:
- Whether the local model identifies phishing or not, on every
  classification
- Whether the server-side models identify phishing or not, every time
  we contact Safe Browsing. This can also be used to determine total
  pings sent to Safe Browsing.
- What the current model version is. While this is indirectly
  controlled by the Finch config, measuring it directly can detect
  mistakes made in the config or on the server-side.

Fixed: 1128205
Change-Id: Ia3e3036c7ce2dc9e3e6814bd626897ca0d055698
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2416063Reviewed-by: Bettina Dea <bdea@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Cr-Commit-Position: refs/heads/master@{#808575}

chrome/browser/safe_browsing/client_side_detection_host.cc

@@ -504,6 +504,9 @@ void ClientSideDetectionHost::PhishingDetectionDone(
       verdict->clear_phash_dimension_size();
     }
 
+    base::UmaHistogramBoolean("SBClientPhishing.LocalModelDetectsPhishing",
+                              verdict->is_phishing());
+
     // We only send phishing verdict to the server if the verdict is phishing or
     // if a SafeBrowsing interstitial was already shown for this site.  E.g., a
     // phishing interstitial was shown but the user clicked
@@ -525,6 +528,8 @@ void ClientSideDetectionHost::PhishingDetectionDone(
 void ClientSideDetectionHost::MaybeShowPhishingWarning(GURL phishing_url,
                                                        bool is_phishing) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  base::UmaHistogramBoolean("SBClientPhishing.ServerModelDetectsPhishing",
+                            is_phishing);
   if (is_phishing) {
     DCHECK(web_contents());
     if (ui_manager_.get()) {

chrome/browser/safe_browsing/client_side_model_loader.cc

@@ -11,6 +11,7 @@
 #include "base/files/file_path.h"
 #include "base/location.h"
 #include "base/memory/weak_ptr.h"
+#include "base/metrics/histogram_functions.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
@@ -251,6 +252,8 @@ void ModelLoader::OnURLLoaderComplete(
     model_str_.assign(data);
     model_.swap(model);
     model_status = MODEL_SUCCESS;
+    base::UmaHistogramSparse("SBClientPhishing.ClientModelVersionFetched",
+                             model_->version());
   }
   EndFetch(model_status, max_age);
 }

tools/metrics/histograms/histograms.xml

@@ -151398,6 +151398,16 @@ Safe Browsing lookups, which is critical for security. -->
   </summary>
 </histogram>
 
+<histogram name="SBClientPhishing.ClientModelVersionFetched" units="version"
+    expires_after="2021-09-17">
+  <owner>drubery@chromium.org</owner>
+  <owner>chrome-safebrowsing-alerts@google.com</owner>
+  <summary>
+    Records the version of the local phishing detection model fetched. This
+    histogram is logged each time we load a model.
+  </summary>
+</histogram>
+
 <histogram name="SBClientPhishing.DOMFeatureChunkTime" units="ms"
     expires_after="M77">
   <owner>gab@chromium.org</owner>
@@ -151497,6 +151507,17 @@ Safe Browsing lookups, which is critical for security. -->
   </summary>
 </histogram>
 
+<histogram name="SBClientPhishing.LocalModelDetectsPhishing"
+    enum="BooleanIsPhishing" expires_after="2021-09-17">
+  <owner>drubery@chromium.org</owner>
+  <owner>chrome-safebrowsing-alerts@google.com</owner>
+  <summary>
+    Records whether the local phishing detection model detects phishing. This
+    histogram is logged each time the model is run (roughly on every navigation
+    to a non-allowlisted site)
+  </summary>
+</histogram>
+
 <histogram name="SBClientPhishing.PageCapturedMatchesBrowserURL"
     enum="BooleanMatched" expires_after="2021-01-27">
   <owner>drubery@chromium.org</owner>
@@ -151602,6 +151623,17 @@ Safe Browsing lookups, which is critical for security. -->
   </summary>
 </histogram>
 
+<histogram name="SBClientPhishing.ServerModelDetectsPhishing"
+    enum="BooleanIsPhishing" expires_after="2021-09-17">
+  <owner>drubery@chromium.org</owner>
+  <owner>chrome-safebrowsing-alerts@google.com</owner>
+  <summary>
+    Records whether the server-side phishing detection model detects phishing.
+    This histogram is logged each time we contact Safe Browsing to evaluate
+    whether a site is phishing.
+  </summary>
+</histogram>
+
 <histogram name="SBClientPhishing.SkipClassificationReason"
     enum="SBClientPhishingSkipClassificationReason" expires_after="2020-02-16">
   <obsolete>