Malware scan verdict SCAN_FAILURE should be a failure in UMA

When recording metrics for malware deep scanning, every verdict that is
not VERDICT_UNSPECIFIED is a success. But SCAN_FAILURE should count as
failure.

Change-Id: I961f19d4a719be53ab04d6f39caf083f919a392a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2134914
Auto-Submit: Daniel Rubery <drubery@chromium.org>
Reviewed-by: Dominique Fauteux-Chapleau <domfc@chromium.org>
Commit-Queue: Dominique Fauteux-Chapleau <domfc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756251}

chrome/browser/safe_browsing/cloud_content_scanning/deep_scanning_utils.cc

@@ -173,11 +173,22 @@ void RecordDeepScanMetrics(DeepScanAccessPoint access_point,
                                  ? response.dlp_scan_verdict().status() ==
                                        DlpDeepScanningVerdict::SUCCESS
                                  : true;
-  bool malware_verdict_success =
-      response.has_malware_scan_verdict()
-          ? response.malware_scan_verdict().verdict() !=
-                MalwareDeepScanningVerdict::VERDICT_UNSPECIFIED
-          : true;
+
+  bool malware_verdict_success = true;
+  if (response.has_malware_scan_verdict()) {
+    switch (response.malware_scan_verdict().verdict()) {
+      case MalwareDeepScanningVerdict::VERDICT_UNSPECIFIED:
+      case MalwareDeepScanningVerdict::SCAN_FAILURE:
+        malware_verdict_success = false;
+        break;
+      case MalwareDeepScanningVerdict::MALWARE:
+      case MalwareDeepScanningVerdict::UWS:
+      case MalwareDeepScanningVerdict::CLEAN:
+        malware_verdict_success = true;
+        break;
+    }
+  }
+
   bool success = dlp_verdict_success && malware_verdict_success;
   std::string result_value = BinaryUploadServiceResultToString(result, success);