Add style-barriers to fast/events/mouse-cursor-image-set{,-svg}.html

This makes sure that the requests for the cursor resources has been
issued before the following loadImages(...) call.

Bug: 1137716, 1138589
Change-Id: I691360327c0d4f70f8eb50fdae224ab53dcc6111
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2479523
Commit-Queue: Stephen Chenney <schenney@chromium.org>
Auto-Submit: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817978}

third_party/blink/web_tests/fast/events/mouse-cursor-image-set-svg.html

@@ -52,6 +52,13 @@ function runTests() {
         checkCursors();
         // Repeat in high-dpi mode
         testRunner.setBackingScaleFactor(2, function() {
+            // Flush style (and layout) to ensure that requests for the (cursor) resources
+            // referenced by style has been issued. This means that the ordering request performed
+            // below will be able to re-use the same (internal) resource if it is still pending.
+            // If the actual cursor request has already completed before the ordering request is
+            // issued then the ordering request will not re-use the same resource, but ordering is
+            // still guaranteed in that case.
+            testContainer.offsetTop;
             // Failed images are apparently reset on scale factor change.
             loadImages([{ url: 'doesntexist.svg', error: true }],
                         function() {

third_party/blink/web_tests/fast/events/mouse-cursor-image-set.html

@@ -53,6 +53,13 @@ function runTests() {
         checkCursors();
         // Repeat in high-dpi mode
         testRunner.setBackingScaleFactor(2, function() {
+            // Flush style (and layout) to ensure that requests for the (cursor) resources
+            // referenced by style has been issued. This means that the ordering request performed
+            // below will be able to re-use the same (internal) resource if it is still pending.
+            // If the actual cursor request has already completed before the ordering request is
+            // issued then the ordering request will not re-use the same resource, but ordering is
+            // still guaranteed in that case.
+            testContainer.offsetTop;
             // Failed images are apparently reset on scale factor change.
             loadImages([{ url: 'doesntexist.png', error: true }],
                         function() {