cros: Disable WindowSelectorTest.DraggingWithTwoFingers.

Flaky in mash.

TBR=oshima@chromium.org

Bug: 827435
Change-Id: I0563bd2b139d9f1ee4be1117a064e6dc29973fc2
Reviewed-on: https://chromium-review.googlesource.com/998052Reviewed-by: Sammie Quon <sammiequon@chromium.org>
Commit-Queue: Sammie Quon <sammiequon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548432}

ash/wm/overview/window_selector_unittest.cc

@@ -2908,7 +2908,8 @@ TEST_F(WindowSelectorTest, ShadowBounds) {
 }
 
 // Verify that attempting to drag with a secondary finger works as expected.
-TEST_F(WindowSelectorTest, DraggingWithTwoFingers) {
+// Flaky, see https://crbug.com/827435.
+TEST_F(WindowSelectorTest, DISABLED_DraggingWithTwoFingers) {
   std::unique_ptr<aura::Window> window1 = CreateTestWindow();
   std::unique_ptr<aura::Window> window2 = CreateTestWindow();