AW: remove obsolete check for Safe Browsing user-opt-out

This removes obsolete code in open source. This setting doesn't actually
exist on AOSP devices (it's a Google setting), and this wasn't a
reliable way of checking it.

Instead, we check SafetyNetClient#isVerifyAppsEnabled() within private
code. This has been implemented in internal CL #391708

Bug: 701621, 700606
Test: Manual - toggled the setting on/off, testing on L-O devices
Change-Id: I46c728cb4b553ae07c6383246df279d05102879b
Reviewed-on: https://chromium-review.googlesource.com/529710
Reviewed-by: Selim Gurun <sgurun@chromium.org>
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#478447}

android_webview/java/src/org/chromium/android_webview/AwSafeBrowsingConfigHelper.java

@@ -4,13 +4,9 @@
 
 package org.chromium.android_webview;
 
-import android.annotation.SuppressLint;
-import android.content.ContentResolver;
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
-import android.os.AsyncTask;
-import android.provider.Settings;
 
 import org.chromium.base.CommandLine;
 import org.chromium.base.Log;
@@ -26,25 +22,15 @@ public class AwSafeBrowsingConfigHelper {
     private static final String OPT_IN_META_DATA_STR = "android.webkit.WebView.EnableSafeBrowsing";
 
     public static void maybeInitSafeBrowsingFromSettings(final Context appContext) {
-        if (AwSafeBrowsingConfigHelper.shouldEnableSafeBrowsingSupport(appContext)) {
-            // Assume safebrowsing on by default initially.
+        if (CommandLine.getInstance().hasSwitch(AwSwitches.WEBVIEW_ENABLE_SAFEBROWSING_SUPPORT)
+                || appHasOptedIn(appContext)) {
+            // Assume safebrowsing on by default initially. If GMS is available, we later use
+            // isVerifyAppsEnabled() to check if "Scan device for security threats" has been checked
+            // by the user.
             AwContentsStatics.setSafeBrowsingEnabled(true);
-            // Fetch Android settings related to safe-browsing in the background.
-            AsyncTask.THREAD_POOL_EXECUTOR.execute(new Runnable() {
-                @Override
-                public void run() {
-                    AwContentsStatics.setSafeBrowsingEnabled(
-                            isScanDeviceForSecurityThreatsEnabled(appContext));
-                }
-            });
         }
     }
 
-    private static boolean shouldEnableSafeBrowsingSupport(Context appContext) {
-        return CommandLine.getInstance().hasSwitch(AwSwitches.WEBVIEW_ENABLE_SAFEBROWSING_SUPPORT)
-                || appHasOptedIn(appContext);
-    }
-
     private static boolean appHasOptedIn(Context appContext) {
         try {
             ApplicationInfo info = appContext.getPackageManager().getApplicationInfo(
@@ -63,14 +49,6 @@ private static boolean appHasOptedIn(Context appContext) {
         }
     }
 
-    @SuppressLint("NewApi") // android.provider.Settings.Global#getInt requires API level 17
-    private static boolean isScanDeviceForSecurityThreatsEnabled(Context applicationContext) {
-        // Determine if the "Scan device for security threats" functionality is enabled in
-        // Android->System->Google->Security settings.
-        ContentResolver contentResolver = applicationContext.getContentResolver();
-        return Settings.Secure.getInt(contentResolver, "package_verifier_user_consent", 1) > 0;
-    }
-
     // Not meant to be instantiated.
     private AwSafeBrowsingConfigHelper() {}
 }