Omnibox UI Experiments: Favicons in fieldtrial testing config.

Bug: 794201
Change-Id: I00e8041f87cc7ecc4846d7e8dba812a498f816c9
Reviewed-on: https://chromium-review.googlesource.com/902803Reviewed-by: Mark Pearson <mpearson@chromium.org>
Commit-Queue: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534543}

testing/variations/fieldtrial_testing_config.json

@@ -2402,6 +2402,7 @@
                     "enable_features": [
                         "OmniboxUIExperimentHideSuggestionUrlScheme",
                         "OmniboxUIExperimentHideSuggestionUrlTrivialSubdomains",
+                        "OmniboxUIExperimentShowSuggestionFavicons",
                         "OmniboxUIExperimentSwapTitleAndUrl",
                         "OmniboxUIExperimentVerticalMargin"
                     ]