disable TestFocusEditableElements on linux

TBR=afakhry@chromium.org

Bug: 1049178
Change-Id: I82ef50ebf23e905f45c0bcdc8f3ac4b31cfd026c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2075400Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#744879}

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

@@ -749,8 +749,9 @@ IN_PROC_BROWSER_TEST_F(TopControlsSlideControllerTest, TestClosingATab) {
                                TopChromeShownState::kFullyHidden);
 }
 
+// Disabled for flakes. See http://crbug.com/1049178
 IN_PROC_BROWSER_TEST_F(TopControlsSlideControllerTest,
-                       TestFocusEditableElements) {
+                       DISABLE_TestFocusEditableElements) {
   ToggleTabletMode();
   ASSERT_TRUE(GetTabletModeEnabled());
   EXPECT_TRUE(top_controls_slide_controller()->IsEnabled());