Revert "[omnibox] Steady State Elisions - Enable flag by default"

This reverts commit 8967c490.

Reason for revert: Holding off until M76

Original change's description:
> [omnibox] Steady State Elisions - Enable flag by default
>
> To prepare for launch, enabling these dy default on tip of tree.
>
> Bug: 842236
> Change-Id: I0d40540fcfb6262238670ccfbcbe3d7f371e05e2
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1577488
> Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
> Commit-Queue: Tommy Li <tommycli@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#652916}

TBR=tommycli@chromium.org,jdonnelly@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 842236
Change-Id: I7d07efad3e5aafd8bfe89de992eb4d9d2f4b9f98
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1596221Reviewed-by: Tommy Li <tommycli@chromium.org>
Reviewed-by: Justin Donnelly <jdonnelly@chromium.org>
Auto-Submit: Tommy Li <tommycli@chromium.org>
Commit-Queue: Tommy Li <tommycli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#656832}

components/omnibox/common/omnibox_features.cc

@@ -21,15 +21,25 @@ const base::Feature kHideFileUrlScheme {
 
 // Feature used to hide the scheme from steady state URLs displayed in the
 // toolbar. It is restored during editing.
-const base::Feature kHideSteadyStateUrlScheme{
-    "OmniboxUIExperimentHideSteadyStateUrlScheme",
-    base::FEATURE_ENABLED_BY_DEFAULT};
+const base::Feature kHideSteadyStateUrlScheme {
+  "OmniboxUIExperimentHideSteadyStateUrlScheme",
+#if defined(OS_IOS)
+      base::FEATURE_ENABLED_BY_DEFAULT
+#else
+      base::FEATURE_DISABLED_BY_DEFAULT
+#endif
+};
 
 // Feature used to hide trivial subdomains from steady state URLs displayed in
 // the toolbar. It is restored during editing.
-const base::Feature kHideSteadyStateUrlTrivialSubdomains{
-    "OmniboxUIExperimentHideSteadyStateUrlTrivialSubdomains",
-    base::FEATURE_ENABLED_BY_DEFAULT};
+const base::Feature kHideSteadyStateUrlTrivialSubdomains {
+  "OmniboxUIExperimentHideSteadyStateUrlTrivialSubdomains",
+#if defined(OS_IOS)
+      base::FEATURE_ENABLED_BY_DEFAULT
+#else
+      base::FEATURE_DISABLED_BY_DEFAULT
+#endif
+};
 
 // Feature used to hide the path, query and ref from steady state URLs
 // displayed in the toolbar. It is restored during editing.