Disable test which times out in component builds

PreviewsProberBrowserTest.NetworkChange reliably times out for me
locally and on the ToTLinux buildbot with these gn args:
  is_debug = false
  symbol_level = 1
  is_component_build=true

Disable the test until it can be fixed.

TBR=robertogden@chromium.org

Bug: 985099
Change-Id: Icd67ae1c7babc0d7aebdbd72b3bb30a4754e2bc6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1706544Reviewed-by: Reid Kleckner <rnk@chromium.org>
Commit-Queue: Reid Kleckner <rnk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#678468}

chrome/browser/previews/previews_prober_browsertest.cc

@@ -7,6 +7,7 @@
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/run_loop.h"
+#include "build/build_config.h"
 #include "chrome/browser/previews/previews_prober.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
@@ -161,7 +162,14 @@ IN_PROC_BROWSER_TEST_F(PreviewsProberBrowserTest, Timeout) {
   EXPECT_FALSE(prober.LastProbeWasSuccessful().value());
 }
 
-IN_PROC_BROWSER_TEST_F(PreviewsProberBrowserTest, NetworkChange) {
+// TODO(crbug.com/985099): Test times out in component builds on Linux.
+#if defined(OS_LINUX) && defined(COMPONENT_BUILD)
+#define MAYBE_NetworkChange DISABLED_NetworkChange
+#else
+#define MAYBE_NetworkChange NetworkChange
+#endif
+
+IN_PROC_BROWSER_TEST_F(PreviewsProberBrowserTest, MAYBE_NetworkChange) {
   GURL url = TestURLWithPath("/ok");
   TestDelegate delegate;
   net::HttpRequestHeaders headers;