[Sheriff] Disabling ConstrainedWebDialogBrowserTest.BasicTest due to flaky crash.

TBR=dpapad@chromium.org

Bug: 1020490
Change-Id: I853e6eb07357bdff23435577edc88fb93e5b12c3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1895331Reviewed-by: Armando Miraglia <armax@chromium.org>
Commit-Queue: Armando Miraglia <armax@chromium.org>
Cr-Commit-Position: refs/heads/master@{#711669}

chrome/browser/ui/webui/constrained_web_dialog_ui_browsertest.cc

@@ -108,7 +108,13 @@ class ConstrainedWebDialogBrowserTest : public InProcessBrowserTest {
 };
 
 // Tests that opening/closing the constrained window won't crash it.
-IN_PROC_BROWSER_TEST_F(ConstrainedWebDialogBrowserTest, BasicTest) {
+// Flaky on trusty builder: http://crbug.com/1020490.
+#if defined(OS_LINUX)
+#define MAYBE_BasicTest DISABLED_BasicTest
+#else
+#define MAYBE_BasicTest BasicTest
+#endif
+IN_PROC_BROWSER_TEST_F(ConstrainedWebDialogBrowserTest, MAYBE_BasicTest) {
   auto delegate = std::make_unique<ui::test::TestWebDialogDelegate>(
       GURL(chrome::kChromeUIConstrainedHTMLTestURL));
   WebContents* web_contents =