Fix flickering tooltips in Chrome when the tip container overlaps the triggering element

Summary:
Fixes T8440. See that task for discussion.

Ref T13216. See PHI976.

Test Plan:
In Chrome, hovered a timestamp and moved the mouse up to the "overlap" area (see T8440). Before: flickered like crazy. After: no flickering.

(I couldn't reproduce the original issue in modern Firefox or Safari.)

Reviewers: amckinley, avivey

Reviewed By: avivey

Maniphest Tasks: T8440, T13216

Differential Revision: https://secure.phabricator.com/D19808

Author: epriestley

resources/celerity/map.php

@@ -9,7 +9,7 @@
   'names' => array(
     'conpherence.pkg.css' => 'e68cf1fa',
     'conpherence.pkg.js' => '15191c65',
-    'core.pkg.css' => '2574c199',
+    'core.pkg.css' => 'cff4ff6f',
     'core.pkg.js' => 'b5a949ca',
     'differential.pkg.css' => '06dc617c',
     'differential.pkg.js' => 'c1cfa143',
@@ -32,7 +32,7 @@
     'rsrc/css/aphront/phabricator-nav-view.css' => '694d7723',
     'rsrc/css/aphront/table-view.css' => '8c9bbafe',
     'rsrc/css/aphront/tokenizer.css' => '15d5ff71',
-    'rsrc/css/aphront/tooltip.css' => '173b9431',
+    'rsrc/css/aphront/tooltip.css' => 'cb1397a4',
     'rsrc/css/aphront/typeahead-browse.css' => 'f2818435',
     'rsrc/css/aphront/typeahead.css' => 'a4a21016',
     'rsrc/css/application/almanac/almanac.css' => 'dbb9b3af',
@@ -521,7 +521,7 @@
     'aphront-panel-view-css' => '8427b78d',
     'aphront-table-view-css' => '8c9bbafe',
     'aphront-tokenizer-control-css' => '15d5ff71',
-    'aphront-tooltip-css' => '173b9431',
+    'aphront-tooltip-css' => 'cb1397a4',
     'aphront-typeahead-control-css' => 'a4a21016',
     'application-search-view-css' => '787f5b76',
     'auth-css' => '0877ed6e',

webroot/rsrc/css/aphront/tooltip.css

@@ -5,6 +5,12 @@
 .jx-tooltip-container {
   position: absolute;
   padding: 5px;
+
+  /* In Chrome, moving the cursor into the empty space next to the "caret" on
+     the caret side of the tooltip can cause the tooltip to flicker rapidly
+     because the cursor hits the container. To stop this, prevent cursor
+     events on the container. See T8440. */
+  pointer-events: none;
 }
 
 .jx-tooltip-appear {