[DevTools] Get rid of target observers based on capabilities

We don't actually need these - we can use model observers instead.

Bug: 882467
Change-Id: If847fcf4f2968430821de316e3b346a25a2a3592
Reviewed-on: https://chromium-review.googlesource.com/c/1311916
Commit-Queue: Dmitry Gozman <[email protected]>
Reviewed-by: Joel Einbinder <[email protected]>
Cr-Original-Commit-Position: refs/heads/master@{#604605}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 1c39a2116d695b78dc154b48305728939650b3ad
diff --git a/front_end/resources/ClearStorageView.js b/front_end/resources/ClearStorageView.js
index 2255c5f..f63288f 100644
--- a/front_end/resources/ClearStorageView.js
+++ b/front_end/resources/ClearStorageView.js
@@ -61,7 +61,7 @@
     this._appendItem(caches, Common.UIString('Cache storage'), 'cache_storage');
     this._appendItem(caches, Common.UIString('Application cache'), 'appcache');
 
-    SDK.targetManager.observeTargets(this, SDK.Target.Capability.Browser);
+    SDK.targetManager.observeTargets(this);
   }
 
   /**