[Flaky] Disable timing-dependent FlingControllerTest

Adding another test to the pile of flaky test in this file. See bugs for
recent failures.

TBR=sahel@chromium.org,dtapuska@chromium.org

Bug: 836996, 875186
Change-Id: Ie8b3565a9f785304f60ca2e2dac1c6ff77f30fb4
Reviewed-on: https://chromium-review.googlesource.com/1179827Reviewed-by: Friedrich Horschig <fhorschig@chromium.org>
Commit-Queue: Friedrich Horschig <fhorschig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#584055}

content/browser/renderer_host/input/fling_controller_unittest.cc

@@ -259,7 +259,9 @@ TEST_F(FlingControllerTest,
   EXPECT_EQ(0.f, last_sent_wheel_.delta_y);
 }
 
-TEST_F(FlingControllerTest, ControllerSendsGSEWhenTouchscreenFlingIsOver) {
+// TODO(https://crbug.com/836996): Timing-dependent flakes on some platforms.
+TEST_F(FlingControllerTest,
+       DISABLED_ControllerSendsGSEWhenTouchscreenFlingIsOver) {
   base::TimeTicks progress_time = base::TimeTicks::Now();
   SimulateFlingStart(blink::kWebGestureDeviceTouchscreen,
                      gfx::Vector2dF(100, 0));