[Linux][Flaky] Disable TabRestoreTest.RestoreWindowBounds on Linux only

This test is very flaky for quite a while now. For details, check the
linked bug.

TBR=ramyan@chromium.org, sky@chromium.org

Bug: 871010
Change-Id: I5d64a708f84d11a9b4981edc2cf53ad6b1a4151d
Reviewed-on: https://chromium-review.googlesource.com/1181048Reviewed-by: Friedrich Horschig <fhorschig@chromium.org>
Commit-Queue: Friedrich Horschig <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584424}

chrome/browser/sessions/tab_restore_browsertest.cc

@@ -429,7 +429,13 @@ IN_PROC_BROWSER_TEST_F(TabRestoreTest, RestoreIntoSameWindow) {
 
 // Open a window with two tabs, close the window, then restore the window.
 // Ensure that the restored window has the expected bounds.
-IN_PROC_BROWSER_TEST_F(TabRestoreTest, RestoreWindowBounds) {
+#if defined(OS_LINUX)
+// Frequently hits "Check failed: is_loading_". See http://crbug.com/871010.
+#define MAYBE_RestoreWindowBounds DISABLED_RestoreWindowBounds
+#else
+#define MAYBE_RestoreWindowBounds RestoreWindowBounds
+#endif
+IN_PROC_BROWSER_TEST_F(TabRestoreTest, MAYBE_RestoreWindowBounds) {
   // Create a browser window with two tabs.
   ui_test_utils::NavigateToURLWithDisposition(
       browser(), url1_, WindowOpenDisposition::CURRENT_TAB,