Makes a check in ~NotificationPlatformBridgeLinuxImpl() non-fatal.

This DCHECK is causing tests in components unrelated to notifications to
be flaky.

Change it to DLOG_IF(ERROR.. so that those components can retain their
test coverage.

Bug: 859061, 988160
Change-Id: I01a5cfeccc9907c64f7afc9d9235a1ad0cb6179e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2584433Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836816}

chrome/browser/notifications/notification_platform_bridge_linux.cc

@@ -432,7 +432,10 @@ class NotificationPlatformBridgeLinuxImpl
   };
 
   ~NotificationPlatformBridgeLinuxImpl() override {
-    DCHECK(clean_up_on_task_runner_called_);
+    // TODO(crbug/859061): This should DCHECK, but doing so makes tests in
+    // components unrelated to notifications flaky. Log instead so that those
+    // tests can retain test coverage.
+    DLOG_IF(ERROR, !clean_up_on_task_runner_called_) << "Not cleaned up";
   }
 
   void Observe(int type,