Revert 222090 "<webview>: Cleanup WebRequest event listeners whe..."
Browser test WebViewTest.Shim_TestWebRequestListenerSurvivesReparenting
failed on win xp:
http://build.chromium.org/p/chromium.win/builders/XP%20Tests%20%283%29/builds/24239
> <webview>: Cleanup WebRequest event listeners when embedder destroyed
>
> <webivew> WebRequest event listeners should survive reparenting of the <webview> within the same embedder WebContents. Currently, event listeners are lost when the <webview> is removed from the DOM. This CL solves this problem.
>
> Note that there is still a problem where custom elements break if the original page that created the element is closed. I have written a test that exercises this problem and I've left the test disabled until we fix the problem.
>
> BUG=281551
> Test=WebViewTest.Shim_TestWebRequestListenerSurvivesReparenting
>
> Review URL: https://chromiumcodereview.appspot.com/
23514016
TBR=fsamuel@chromium.org
Review URL: https://codereview.chromium.org/
23965004
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@222123 0039d316-1c4b-4281-b951-d872f2087c98