Improve intent: URI handling

components/arc/common/intent_helper.mojom

Index: components/arc/common/intent_helper.mojom
diff --git a/components/arc/common/intent_helper.mojom b/components/arc/common/intent_helper.mojom
index a371fe955c2f180fe998e64a5548c8291fb0917c..9c00a9f891004656824a731f31bbefa4da543c84 100644
--- a/components/arc/common/intent_helper.mojom
+++ b/components/arc/common/intent_helper.mojom
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Next MinVersion: 14
+// Next MinVersion: 15
 
 module arc.mojom;
 
@@ -57,6 +57,9 @@ struct IntentHandlerInfo {
   [MinVersion=4] ActionType action_type;
   [MinVersion=6] bool is_preferred;
   [MinVersion=11] string? action;  // e.g. "android.intent.action.VIEW"
+  // RequestUrlHandlerList may fill |fallback_url| when it is called with an
+  // intent: URL.
+  [MinVersion=14] string? fallback_url;
 };
 
 // Describes an activity.