DL: Switch depends_on to implied_by for DisplayLocking/CSSContentSize.

depends_on means that the feature is only enabled if the depended-on
feature is enabled. implied_by means that the feature is automatically
enabled when the implied-by feature is enabled.

We want CSSContentSize to be implied-by DisplayLocking, not DisplayLocking
to depend-on CSSContentSize.

R=chrishtr@chromium.org, rakina@chromium.org

Change-Id: I39f908dee3d7a0b99d1f727b41f76ae3c1a8efcd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1863564
Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
Reviewed-by: Rakina Zata Amni <rakina@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706545}

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -395,6 +395,7 @@
       // Support for CSS content-size property.
       // http://tabatkins.github.io/specs/css-content-size/
       name: "CSSContentSize",
+      implied_by: ["DisplayLocking"],
       status: "experimental",
     },
     {
@@ -544,7 +545,6 @@
     {
       name: "DisplayLocking",
       origin_trial_feature_name: "DisplayLocking",
-      depends_on: ["CSSContentSize"],
       status: "experimental",
     },
     {