Use task id to determine if Preferences should be finished

chrome/android/java/src/org/chromium/chrome/browser/preferences/Preferences.java

Index: chrome/android/java/src/org/chromium/chrome/browser/preferences/Preferences.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/Preferences.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/Preferences.java
index 6cd85f0dfb04e04c65d4031f0469df921db7bdd4..b62a1e4f09700a784b7fda9a92bbf4b4adb9e8f3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/Preferences.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/Preferences.java
@@ -157,13 +157,16 @@ public class Preferences extends AppCompatActivity implements
 
         // Prevent the user from interacting with multiple instances of Preferences at the same time
         // (e.g. in multi-instance mode on a Samsung device), which would cause many fun bugs.
-        if (sResumedInstance != null && sResumedInstance != this && !mIsNewlyCreated) {
+        if (sResumedInstance != null && sResumedInstance.getTaskId() != getTaskId()
+                && !mIsNewlyCreated) {
             // This activity was unpaused or recreated while another instance of Preferences was
             // already showing. The existing instance takes precedence.
             finish();
         } else {
             // This activity was newly created and takes precedence over sResumedInstance.
-            if (sResumedInstance != null && sResumedInstance != this) sResumedInstance.finish();
+            if (sResumedInstance != null && sResumedInstance.getTaskId() != getTaskId()) {
+                sResumedInstance.finish();
+            }
 
             sResumedInstance = this;
             mIsNewlyCreated = false;