Force freezing of non timers in background in all situations.

Desktop has not shipped the freezing feature yet and it explicitly
always enables this state in the finch config. Ensure this is set via
the code now.

The goal of making this change is that mobile and desktop will be
the same in the code (it always was via finch config). But it will
allow in the future to clean up code related to this.

BUG=967431

Change-Id: I774c3f4173acfc8c1d9d0cf61cf1ac9c7722d67c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1631722Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664763}

third_party/blink/common/features.cc

@@ -211,14 +211,8 @@ const base::Feature kFreezeBackgroundTabOnNetworkIdle{
 
 // Freeze non-timer task queues in background, after allowed grace time.
 // "stop" is a legacy name.
-const base::Feature kStopNonTimersInBackground {
-  "stop-non-timers-in-background",
-#if defined(OS_ANDROID)
-      base::FEATURE_ENABLED_BY_DEFAULT
-#else
-      base::FEATURE_DISABLED_BY_DEFAULT
-#endif
-};
+const base::Feature kStopNonTimersInBackground{
+    "stop-non-timers-in-background", base::FEATURE_ENABLED_BY_DEFAULT};
 
 // Enable text snippets in URL fragments. https://crbug.com/919204.
 const base::Feature kTextFragmentAnchor{"TextFragmentAnchor",