Disable a few `BrowserNavigatorTest`s on linux-chromeos-dbg.

The following tests pretty consistently fail on linux-chromeos-dbg:

BrowserNavigatorTest.CloseSingletonTab
BrowserNavigatorTest.NavigateFromBlankToOptionsInSameTab
BrowserNavigatorTest.NavigateFromNTPToOptionsInSameTab
BrowserNavigatorTest.NavigateFromNTPToOptionsPageInSameTab

https://ci.chromium.org/p/chromium/builders/ci/linux-chromeos-dbg/15245 is a recent example run. https://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=BrowserNavigatorTest.NavigateFrom is a broader view.

TBR=ellyjones@chromium.org

Bug: 1024166
Change-Id: Ia05dc43c8948fb0ba26615f3f9f5c791705d876c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1912707Reviewed-by: Mike West <mkwst@chromium.org>
Commit-Queue: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714875}

chrome/browser/ui/browser_navigator_browsertest.cc

@@ -1428,8 +1428,16 @@ IN_PROC_BROWSER_TEST_F(BrowserNavigatorTest,
             browser()->tab_strip_model()->GetActiveWebContents()->GetURL());
 }
 
+// TODO(1024166): Timing out on linux-chromeos-dbg.
+#if defined(OS_CHROMEOS)
+#define MAYBE_NavigateFromBlankToOptionsInSameTab \
+  DISABLED_NavigateFromBlankToOptionsInSameTab
+#else
+#define MAYBE_NavigateFromBlankToOptionsInSameTab \
+  NavigateFromBlankToOptionsInSameTab
+#endif
 IN_PROC_BROWSER_TEST_F(BrowserNavigatorTest,
-                       NavigateFromBlankToOptionsInSameTab) {
+                       MAYBE_NavigateFromBlankToOptionsInSameTab) {
   NavigateParams params(MakeNavigateParams());
   params.url = GURL(url::kAboutBlankURL);
   ui_test_utils::NavigateToURL(&params);
@@ -1446,8 +1454,16 @@ IN_PROC_BROWSER_TEST_F(BrowserNavigatorTest,
             browser()->tab_strip_model()->GetActiveWebContents()->GetURL());
 }
 
+// TODO(1024166): Timing out on linux-chromeos-dbg.
+#if defined(OS_CHROMEOS)
+#define MAYBE_NavigateFromNTPToOptionsInSameTab \
+  DISABLED_NavigateFromNTPToOptionsInSameTab
+#else
+#define MAYBE_NavigateFromNTPToOptionsInSameTab \
+  NavigateFromNTPToOptionsInSameTab
+#endif
 IN_PROC_BROWSER_TEST_F(BrowserNavigatorTest,
-                       NavigateFromNTPToOptionsInSameTab) {
+                       MAYBE_NavigateFromNTPToOptionsInSameTab) {
   NavigateParams params(MakeNavigateParams());
   params.url = GURL(chrome::kChromeUINewTabURL);
   ui_test_utils::NavigateToURL(&params);
@@ -1514,8 +1530,16 @@ IN_PROC_BROWSER_TEST_F(BrowserNavigatorTest,
             browser()->tab_strip_model()->GetActiveWebContents()->GetURL());
 }
 
+// TODO(1024166): Timing out on linux-chromeos-dbg.
+#if defined(OS_CHROMEOS)
+#define MAYBE_NavigateFromNTPToOptionsPageInSameTab \
+  DISABLED_NavigateFromNTPToOptionsPageInSameTab
+#else
+#define MAYBE_NavigateFromNTPToOptionsPageInSameTab \
+  NavigateFromNTPToOptionsPageInSameTab
+#endif
 IN_PROC_BROWSER_TEST_F(BrowserNavigatorTest,
-                       NavigateFromNTPToOptionsPageInSameTab) {
+                       MAYBE_NavigateFromNTPToOptionsPageInSameTab) {
   {
     content::WindowedNotificationObserver observer(
         content::NOTIFICATION_LOAD_STOP,
@@ -1597,7 +1621,13 @@ IN_PROC_BROWSER_TEST_F(BrowserNavigatorTest,
             browser()->tab_strip_model()->GetActiveWebContents()->GetURL());
 }
 
-IN_PROC_BROWSER_TEST_F(BrowserNavigatorTest, CloseSingletonTab) {
+// TODO(1024166): Timing out on linux-chromeos-dbg.
+#if defined(OS_CHROMEOS)
+#define MAYBE_CloseSingletonTab DISABLED_CloseSingletonTab
+#else
+#define MAYBE_CloseSingletonTab CloseSingletonTab
+#endif
+IN_PROC_BROWSER_TEST_F(BrowserNavigatorTest, MAYBE_CloseSingletonTab) {
   for (int i = 0; i < 2; ++i) {
     content::WindowedNotificationObserver observer(
         content::NOTIFICATION_LOAD_STOP,