[SB Delayed Warnings] Do not check for CSD if there is a delayed warning

When Delayed Warnings feature detects and delays an interstitial, Client
Side Detection could send another phishy verdict for the same URL. This
causes the interstitial to be undelayed immediately. This CL changes the
CSD behavior so that it never checks if a Delayed Warning observer is
attached to a tab which only happens if a warning is being delayed.

This is manually tested to work both on official and non-official
builds. A follow up CL will add browser tests.

Bug: 1118192
Test: Manual
Change-Id: I418910c35ec692ef23e4295a6b59092cb55d5968
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2364213Reviewed-by: Daniel Rubery <drubery@chromium.org>
Commit-Queue: Mustafa Emre Acer <meacer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799881}

chrome/browser/safe_browsing/client_side_detection_host.cc

@@ -25,6 +25,7 @@
 #include "chrome/browser/safe_browsing/client_side_detection_service.h"
 #include "chrome/browser/safe_browsing/client_side_detection_service_factory.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
+#include "chrome/browser/safe_browsing/user_interaction_observer.h"
 #include "chrome/common/pref_names.h"
 #include "components/prefs/pref_service.h"
 #include "components/safe_browsing/content/common/safe_browsing.mojom-shared.h"
@@ -126,6 +127,12 @@ class ClientSideDetectionHost::ShouldClassifyUrlRequest
       DontClassifyForPhishing(NO_CLASSIFY_WHITELISTED_BY_POLICY);
     }
 
+    // If the tab has a delayed warning, ignore this second verdict. We don't
+    // want to immediately undelay a page that's already blocked as phishy.
+    if (SafeBrowsingUserInteractionObserver::FromWebContents(web_contents_)) {
+      DontClassifyForPhishing(NO_CLASSIFY_HAS_DELAYED_WARNING);
+    }
+
     // We lookup the csd-whitelist before we lookup the cache because
     // a URL may have recently been whitelisted.  If the URL matches
     // the csd-whitelist we won't start phishing classification.  The
@@ -169,6 +176,7 @@ class ClientSideDetectionHost::ShouldClassifyUrlRequest
     NO_CLASSIFY_SCHEME_NOT_SUPPORTED = 11,
     NO_CLASSIFY_WHITELISTED_BY_POLICY = 12,
     CLASSIFY = 13,
+    NO_CLASSIFY_HAS_DELAYED_WARNING = 14,
 
     NO_CLASSIFY_MAX  // Always add new values before this one.
   };

tools/metrics/histograms/enums.xml

@@ -62323,6 +62323,7 @@ https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_2.7.1.pdf
   <int value="11" label="SCHEME_NOT_SUPPORTED"/>
   <int value="12" label="WHITELISTED_BY_POLICY"/>
   <int value="13" label="CLASSIFY"/>
+  <int value="14" label="NO_CLASSIFY_HAS_DELAYED_WARNING"/>
 </enum>
 
 <enum name="SBClientDownloadCheckDownloadStats">