Add the extended reporting checkbox to the malware interstitial v3

chrome/browser/resources/safe_browsing/safe_browsing_v3.js

Index: chrome/browser/resources/safe_browsing/safe_browsing_v3.js
diff --git a/chrome/browser/resources/safe_browsing/safe_browsing_v3.js b/chrome/browser/resources/safe_browsing/safe_browsing_v3.js
index 519a5824b94bd040146f5b331f38b392eebe42ff..a3bf4eb9c5a94900b9690fd6dc940e2423687628 100644
--- a/chrome/browser/resources/safe_browsing/safe_browsing_v3.js
+++ b/chrome/browser/resources/safe_browsing/safe_browsing_v3.js
@@ -16,3 +16,19 @@ var SB_CMD_TAKE_ME_BACK = 'takeMeBack';
 // Other constants defined in safe_browsing_blocking_page.cc.
 var SB_BOX_CHECKED = 'boxchecked';
 var SB_DISPLAY_CHECK_BOX = 'displaycheckbox';
+
+// This sets up the Extended Safe Browsing Reporting opt-in.
+function setupCheckbox() {
+  if (loadTimeData.getBoolean('ssl')) return;
+  if (loadTimeData.getBoolean('phishing')) return;
+  if (!loadTimeData.getBoolean(SB_DISPLAY_CHECK_BOX)) return;
+
+  $('optin-label').innerHTML = loadTimeData.getString('optinText');
+  $('optin-checkbox').checked = loadTimeData.getBoolean(SB_BOX_CHECKED);
+  $('malware-optin').classList.remove('hidden');
+
+  $('optin-checkbox').addEventListener('click', function() {
+    sendCommand(
+        $('optin-checkbox').checked ? SB_CMD_DO_REPORT : SB_CMD_DONT_REPORT);
+  });
+}