Fix an issue that OMA download is not intercepted on Android

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

Index: chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
index 7f31dbf249289257e275c50429a70be6af242913..0e148501584a2c5a952aea941241d19ae8644d16 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadManagerService.java
@@ -137,6 +137,15 @@ public class DownloadManagerService extends BroadcastReceiver implements
     // Flag to track if we need to post a task to update download notifications.
     private boolean mIsUIUpdateScheduled;
     private int mAutoResumptionLimit = -1;
+    private DownloadManagerRequestInterceptor mDownloadManagerRequestInterceptor;
+
+    /**
+     * Interface to intercept download request to Android DownloadManager. This is implemented by
+     * tests so that we don't need to actually enqueue a download into the Android DownloadManager.
+     */
+    static interface DownloadManagerRequestInterceptor {
+        void interceptDownloadRequest(DownloadItem item, boolean notifyComplete);
+    }
 
     /**
      * Class representing progress of a download.
@@ -243,10 +252,13 @@ public class DownloadManagerService extends BroadcastReceiver implements
     }
 
     @VisibleForTesting
-    protected DownloadManagerService(Context context,
-            DownloadNotifier downloadNotifier,
-            Handler handler,
-            long updateDelayInMillis) {
+    void setDownloadManagerRequestInterceptor(DownloadManagerRequestInterceptor interceptor) {
+        mDownloadManagerRequestInterceptor = interceptor;
+    }
+
+    @VisibleForTesting
+    protected DownloadManagerService(Context context, DownloadNotifier downloadNotifier,
+            Handler handler, long updateDelayInMillis) {
         mContext = context;
         mSharedPrefs = ContextUtils.getAppSharedPreferences();
         // Clean up unused shared prefs. TODO(qinmin): remove this after M61.
@@ -855,6 +867,10 @@ public class DownloadManagerService extends BroadcastReceiver implements
      */
     public void enqueueDownloadManagerRequest(
             final DownloadItem item, boolean notifyCompleted) {
+        if (mDownloadManagerRequestInterceptor != null) {
+            mDownloadManagerRequestInterceptor.interceptDownloadRequest(item, notifyCompleted);
+            return;
+        }
         EnqueueDownloadRequestTask task = new EnqueueDownloadRequestTask(item);
         task.execute(notifyCompleted);
     }
@@ -891,10 +907,12 @@ public class DownloadManagerService extends BroadcastReceiver implements
             request.setMimeType(info.getMimeType());
             try {
                 if (notifyCompleted) {
-                    // Set downloaded file destination to /sdcard/Download or, should it be
-                    // set to one of several Environment.DIRECTORY* dirs depending on mimetype?
-                    request.setDestinationInExternalPublicDir(
-                            Environment.DIRECTORY_DOWNLOADS, info.getFileName());
+                    if (info.getFileName() != null) {
+                        // Set downloaded file destination to /sdcard/Download or, should it be
+                        // set to one of several Environment.DIRECTORY* dirs depending on mimetype?
+                        request.setDestinationInExternalPublicDir(
+                                Environment.DIRECTORY_DOWNLOADS, info.getFileName());
+                    }
                 } else {
                     File dir = new File(mContext.getExternalFilesDir(null), DOWNLOAD_DIRECTORY);
                     if (dir.mkdir() || dir.isDirectory()) {