Enable downloads foreground in chrome://flags.

Enable feature "enable downloads foreground" by default in
chrome://flags to test for M64.

Bug: 747563
Change-Id: I34a1cdd85a89864fd495fc7d403cbcfbb0d54d0b
Reviewed-on: https://chromium-review.googlesource.com/758622Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Joy Ming <jming@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515743}

chrome/common/chrome_features.cc

@@ -185,7 +185,7 @@ const base::Feature kDoodlesOnLocalNtp{"DoodlesOnLocalNtp",
 #if defined(OS_ANDROID)
 // Enables downloads as a foreground service for all versions of Android.
 const base::Feature kDownloadsForeground{"DownloadsForeground",
-                                         base::FEATURE_DISABLED_BY_DEFAULT};
+                                         base::FEATURE_ENABLED_BY_DEFAULT};
 #endif
 
 // Enables Expect CT reporting, which sends reports for opted-in sites