Refactor websocket connections logic with devtool Storage domain to a separate class

telemetry/telemetry/internal/browser/tab.py

 # Copyright 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from telemetry.internal.actions import action_runner
 from telemetry.internal.browser import web_contents
 from telemetry.internal.image_processing import video
-from telemetry.core import exceptions
 
 DEFAULT_TAB_TIMEOUT = 60
 
 
 class Tab(web_contents.WebContents):
   """Represents a tab in the browser
 
   The important parts of the Tab object are in the runtime and page objects.
   E.g.:
       # Navigates the tab to a given url.
@@ skipping 259 matching lines @@
     """Clears storage data for the origin of url.
 
     With assigning 'all' to params.storageTypes, Storage.clearDataForOrigin
     clears all storage of app cache, cookies, file systems, indexed db,
     local storage, shader cache, web sql, service workers and cache storage.
     See StorageHandler::ClearDataForOrigin() for more details.
 
     Raises:
       exceptions.StoryActionError
     """
-    res = self._inspector_backend._websocket.SyncRequest({
-        'method': 'Storage.clearDataForOrigin',
-        'params': {
-            'origin': url,
-            'storageTypes': 'all'
-        }
-    }, timeout)
-    if 'error' in res:
-      raise exceptions.StoryActionError(res['error']['message'])
+    return self._inspector_backend.ClearDataForOrigin(url, timeout)