Fixed launching of multiple instances of download home when tapping notification

chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java

Index: chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java
index b989159158052b5abf18049dd18069fc7d1783b1..048ebcc10535ae18a13604c119f368e0cbbfe824 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java
@@ -140,6 +140,8 @@ public class DownloadUtils {
                 appContext.startActivity(intent);
             } else {
                 // Sits on top of another Activity.
+                intent.addFlags(
+                        Intent.FLAG_ACTIVITY_MULTIPLE_TASK | Intent.FLAG_ACTIVITY_SINGLE_TOP);
                 intent.putExtra(IntentHandler.EXTRA_PARENT_COMPONENT, activity.getComponentName());
                 activity.startActivity(intent);
             }