Disable PrintPreviewUIBrowserTest.InvalidSettingsError because of test flakiness

Bug: 795626
Change-Id: If0016e86ca495cee54bf4b7a845f5adda8e6b65b
TBR: dpapad@chromium.org
Reviewed-on: https://chromium-review.googlesource.com/830993Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/master@{#524647}

chrome/test/data/webui/print_preview/print_preview_ui_browsertest.js

@@ -98,7 +98,9 @@ PrintPreviewUIBrowserTest.prototype = {
   'NoPDFPluginErrorMessage',
   'CustomPaperNames',
   'InitIssuesOneRequest',
-  'InvalidSettingsError',
+  // TODO(https://crbug.com/795626): Re-enable this test when test flakiness on
+  // the Mac bot is fixed.
+  'DISABLED_InvalidSettingsError',
   // TODO(thestig): Re-enable this test when the feature works properly.
   // https://crbug.com/746768
   'DISABLED_GenerateDraft',