sheriff: Disable TopControlsSlideControllerTest.TestClosingATab on ChromeOS

It has been flaky on Chrome OS for a while.

TBR=afakhry@chromium.org

Bug: 1127805
Change-Id: I16d3b25015a6785ccef0edd6db45e7c910dfd4b8


sheriff: Only call GetPreviousURL on committed/error navigations

Speculative fix for https://crbug.com/1127797

TBR=estark@chromium.org

Bug: 1127797
Test: CQ
Change-Id: I0ebc142960a4f9bea3df626123210367df6f8d35
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2409433Reviewed-by: Pavol Marko <pmarko@chromium.org>
Commit-Queue: Pavol Marko <pmarko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#806580}

chrome/browser/ui/views/frame/top_controls_slide_controller_chromeos_browsertest.cc

@@ -745,7 +745,13 @@ IN_PROC_BROWSER_TEST_F(TopControlsSlideControllerTest,
       scrollable_page_contents));
 }
 
-IN_PROC_BROWSER_TEST_F(TopControlsSlideControllerTest, TestClosingATab) {
+#if defined(OS_CHROMEOS)
+// http://crbug.com/1127805: Flaky on Chrome OS builders
+#define MAYBE_TestClosingATab DISABLED_TestClosingATab
+#else
+#define MAYBE_TestClosingATab TestClosingATab
+#endif
+IN_PROC_BROWSER_TEST_F(TopControlsSlideControllerTest, MAYBE_TestClosingATab) {
   ToggleTabletMode();
   ASSERT_TRUE(GetTabletModeEnabled());
   EXPECT_TRUE(top_controls_slide_controller()->IsEnabled());