Add origin trial feature name for ARIA annotations

Link to I2E:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/hxV0yjyS8_4

Bug: 1006767
Change-Id: I26e453bcc5eb21e38388a4f152e85134a22d1531
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1873886
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Auto-Submit: Aaron Leventhal <aleventhal@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#708595}

third_party/blink/renderer/modules/accessibility/ax_object.cc

@@ -2078,8 +2078,8 @@ ax::mojom::Role AXObject::DetermineAriaRoleAttribute() const {
     case ax::mojom::Role::kAnnotationRevision:
     case ax::mojom::Role::kAnnotationSuggestion:
       UseCounter::Count(GetDocument(), WebFeature::kARIAAnnotationRoles);
-      if (!RuntimeEnabledFeatures::
-              AccessibilityExposeARIAAnnotationsEnabled()) {
+      if (!RuntimeEnabledFeatures::AccessibilityExposeARIAAnnotationsEnabled(
+              GetDocument())) {
         role = ax::mojom::Role::kGenericContainer;
       }
       break;

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -100,6 +100,7 @@
     },
     {
       name: "AccessibilityExposeARIAAnnotations",
+      origin_trial_feature_name: "AccessibilityExposeARIAAnnotations",
       status: "experimental",
     },
     {