Add RT Lookup Experiment Enabled in chrome://safe-browsing/#tab-rt-lookup

This flag will be useful for testing on Android, because it takes memory
threshold into account.

Screenshot: http://screen/7NSFgNqotba.png

Bug: 1014202
Change-Id: I5c647c73228a875144df514ea344203cd0e46583
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2024409Reviewed-by: Daniel Rubery <drubery@chromium.org>
Commit-Queue: Xinghui Lu <xinghuilu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735932}

components/safe_browsing/content/web_ui/BUILD.gn

@@ -23,6 +23,7 @@ static_library("web_ui") {
     "//components/safe_browsing/core/browser:referrer_chain_provider",
     "//components/safe_browsing/core/common:safe_browsing_prefs",
     "//components/safe_browsing/core/db:v4_local_database_manager",
+    "//components/safe_browsing/core/realtime:policy_engine",
     "//components/safe_browsing/core/web_ui:constants",
     "//components/strings:components_strings_grit",
     "//components/sync/protocol:protocol",

components/safe_browsing/content/web_ui/resources/safe_browsing.html

@@ -91,6 +91,7 @@
         </tabpanel>
         <tabpanel>
           <h2>RT Lookup Pings</h2>
+          <p id="rt-lookup-experiment-enabled"></p>
           <table id="rt-lookup-ping-list" class="request-response"></table>
         </tabpanel>
         <tabpanel>

components/safe_browsing/content/web_ui/resources/safe_browsing.js

@@ -111,6 +111,9 @@ cr.define('safe_browsing', function() {
       addRTLookupResponse(result);
     });
 
+    cr.sendWithPromise('getRTLookupExperimentEnabled', [])
+        .then((enabled) => addRTLookupExperimentEnabled(enabled));
+
     cr.sendWithPromise('getLogMessages', []).then((logMessages) => {
       logMessages.forEach(function(message) {
         addLogMessage(message);
@@ -272,6 +275,11 @@ cr.define('safe_browsing', function() {
     addResultToTable('rt-lookup-ping-list', result, 1);
   }
 
+  function addRTLookupExperimentEnabled(enabled) {
+    const enabledFormatted = '<b>RT Lookup Experiment Enabled:</b> ' + enabled;
+    $('rt-lookup-experiment-enabled').innerHTML = enabledFormatted;
+  }
+
   function addLogMessage(result) {
     const logDiv = $('log-messages');
     const eventFormatted = "[" + (new Date(result["time"])).toLocaleString() +

components/safe_browsing/content/web_ui/safe_browsing_ui.cc

@@ -32,6 +32,7 @@
 #include "components/safe_browsing/core/common/safe_browsing_prefs.h"
 #include "components/safe_browsing/core/features.h"
 #include "components/safe_browsing/core/proto/csd.pb.h"
+#include "components/safe_browsing/core/realtime/policy_engine.h"
 #include "components/safe_browsing/core/web_ui/constants.h"
 #include "components/strings/grit/components_strings.h"
 #include "components/user_prefs/user_prefs.h"
@@ -1514,6 +1515,17 @@ void SafeBrowsingUIHandler::GetRTLookupResponses(const base::ListValue* args) {
   ResolveJavascriptCallback(base::Value(callback_id), responses_sent);
 }
 
+void SafeBrowsingUIHandler::GetRTLookupExperimentEnabled(
+    const base::ListValue* args) {
+  base::ListValue value;
+  value.Append(base::Value(RealTimePolicyEngine::IsUrlLookupEnabled()));
+
+  AllowJavascript();
+  std::string callback_id;
+  args->GetString(0, &callback_id);
+  ResolveJavascriptCallback(base::Value(callback_id), value);
+}
+
 void SafeBrowsingUIHandler::GetReferrerChain(const base::ListValue* args) {
   std::string url_string;
   args->GetString(1, &url_string);
@@ -1724,6 +1736,10 @@ void SafeBrowsingUIHandler::RegisterMessages() {
       "getRTLookupResponses",
       base::BindRepeating(&SafeBrowsingUIHandler::GetRTLookupResponses,
                           base::Unretained(this)));
+  web_ui()->RegisterMessageCallback(
+      "getRTLookupExperimentEnabled",
+      base::BindRepeating(&SafeBrowsingUIHandler::GetRTLookupExperimentEnabled,
+                          base::Unretained(this)));
   web_ui()->RegisterMessageCallback(
       "getLogMessages",
       base::BindRepeating(&SafeBrowsingUIHandler::GetLogMessages,

components/safe_browsing/content/web_ui/safe_browsing_ui.h

@@ -92,6 +92,10 @@ class SafeBrowsingUIHandler : public content::WebUIMessageHandler {
   // currently open chrome://safe-browsing tab was opened.
   void GetRTLookupResponses(const base::ListValue* args);
 
+  // Show whether real time lookup experiment is enabled. This is useful for
+  // testing on Android, because it also takes memory threshold into account.
+  void GetRTLookupExperimentEnabled(const base::ListValue* args);
+
   // Get the current referrer chain for a given URL.
   void GetReferrerChain(const base::ListValue* args);
 

components/safe_browsing/core/realtime/policy_engine.h

@@ -39,6 +39,7 @@ class RealTimePolicyEngine {
   static bool CanPerformFullURLLookup(content::BrowserContext* browser_context);
 
   friend class SafeBrowsingService;
+  friend class SafeBrowsingUIHandler;
 
  private:
   // Is the feature to perform real-time URL lookup enabled?