Reenable ResourceLoadingHintsBrowserTest on Linux

The plan is to keep a close eye on bots, and disable the tests back
if we see flakiness.

This CL will help us understand which of the tests are failing,
and also get a stack trace (which is now lost).

Bug: 866212
Change-Id: I94ff8ffb7278eff1ad3533d7872c1781e1e38b67
Reviewed-on: https://chromium-review.googlesource.com/1173443Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Commit-Queue: Tarun Bansal <tbansal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582730}

chrome/browser/previews/resource_loading_hints/resource_loading_hints_browsertest.cc

@@ -283,8 +283,8 @@ class ResourceLoadingHintsBrowserTest
 
 // Previews InfoBar (which these tests triggers) does not work on Mac.
 // See crbug.com/782322 for details. Also occasional flakes on win7/linux
-// (crbug.com/789542, crbug.com/866212).
-#if !defined(OS_MACOSX) && !defined(OS_WIN) && !defined(OS_LINUX)
+// (https://crbug.com/789542).
+#if !defined(OS_MACOSX) && !defined(OS_WIN)
 #define MAYBE_ResourceLoadingHintsHttpsWhitelisted \
   ResourceLoadingHintsHttpsWhitelisted
 #define MAYBE_ResourceLoadingHintsHttpsWhitelistedRedirectToHttps \