Disabled flaky browser test.

SitePerProcessHighDPIHitTestBrowserTest.RootWindowTransform/0 and
SitePerProcessHitTestBrowserTest.RootWindowTransform/0 are reported as
flaky. Disabling.

TBR=riajiang@chromium.org

Bug: 871321, 870744
Change-Id: I4003753932b98f83e509dfb0bea5f69b03eb7d1e
Reviewed-on: https://chromium-review.googlesource.com/1164961
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581216}

content/browser/site_per_process_hit_test_browsertest.cc

@@ -1882,12 +1882,13 @@ IN_PROC_BROWSER_TEST_P(SitePerProcessHighDPIHitTestBrowserTest,
 }
 
 #if defined(USE_AURA)
-IN_PROC_BROWSER_TEST_P(SitePerProcessHitTestBrowserTest, RootWindowTransform) {
+IN_PROC_BROWSER_TEST_P(SitePerProcessHitTestBrowserTest,
+                       DISABLED_RootWindowTransform) {
   HitTestRootWindowTransform(shell(), embedded_test_server());
 }
 
 IN_PROC_BROWSER_TEST_P(SitePerProcessHighDPIHitTestBrowserTest,
-                       RootWindowTransform) {
+                       DISABLED_RootWindowTransform) {
   HitTestRootWindowTransform(shell(), embedded_test_server());
 }
 #endif  // defined(USE_AURA)