[chromecast] Re-enable side swipe detection

Not all services have been rewritten to not require side swipe
detection from cast platform. Re-enable for now.

Bug: internal b/143545462
Test: manual
Change-Id: I35f2493e3f2379f239da1a15de867ed71809e8e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1890008Reviewed-by: Alex Sakhartchouk <alexst@chromium.org>
Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Commit-Queue: Ryan Daum <rdaum@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710838}

chromecast/graphics/cast_window_manager_aura.cc

@@ -252,11 +252,10 @@ void CastWindowManagerAura::Setup() {
   system_gesture_event_handler_ =
       std::make_unique<CastSystemGestureEventHandler>(
           system_gesture_dispatcher_.get(), root_window);
-  // No need for the edge swipe detector when side gestures are pass-through.
-  if (!chromecast::IsFeatureEnabled(kEnableSideGesturePassThrough)) {
-    side_swipe_detector_ = std::make_unique<SideSwipeDetector>(
-        system_gesture_dispatcher_.get(), root_window);
-  }
+  // TODO(rdaum): Remove side swipe detection when all services requiring it
+  // have been rewritten.
+  side_swipe_detector_ = std::make_unique<SideSwipeDetector>(
+      system_gesture_dispatcher_.get(), root_window);
 
   // Add rounded corners, but defaulted to hidden until explicitly asked for by
   // a component.