Disable flaky SitePerProcessHitTestBrowserTest.InputEventRouterTouchpadGestureTargetTest

TBR=riajiang@chromium.org

Bug: 838835
Change-Id: Ie69310cde0d51472d3446c57b8bbd66bc703a602
Reviewed-on: https://chromium-review.googlesource.com/1041957Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555710}

content/browser/site_per_process_hit_test_browsertest.cc

@@ -3022,8 +3022,9 @@ IN_PROC_BROWSER_TEST_P(
 }
 #endif  // defined(USE_AURA) || defined(OS_ANDROID)
 
+// Flaky, see crbug.com/838835
 IN_PROC_BROWSER_TEST_P(SitePerProcessHitTestBrowserTest,
-                       InputEventRouterTouchpadGestureTargetTest) {
+                       DISABLED_InputEventRouterTouchpadGestureTargetTest) {
   GURL main_url(embedded_test_server()->GetURL(
       "/frame_tree/page_with_positioned_nested_frames.html"));
   EXPECT_TRUE(NavigateToURL(shell(), main_url));