Remove SigninManager.kChromeSigninEffectiveSite

This was missing from https://codereview.chromium.org/964553002.

Bug: 260022, 350202
Change-Id: I4198ddb70195d70f9307638d6def291022a1b2ac
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1636198Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Commit-Queue: Henrique Ferreiro <hferreiro@igalia.com>
Cr-Commit-Position: refs/heads/master@{#665858}

components/signin/core/browser/signin_manager.h

@@ -46,13 +46,6 @@ class IdentityManager;
 class SigninManager : public SigninManagerBase,
                       public OAuth2TokenService::Observer {
  public:
-  // This is used to distinguish URLs belonging to the special web signin flow
-  // running in the special signin process from other URLs on the same domain.
-  // We do not grant WebUI privilieges / bindings to this process or to URLs of
-  // this scheme; enforcement of privileges is handled separately by
-  // OneClickSigninHelper.
-  static const char kChromeSigninEffectiveSite[];
-
   SigninManager(SigninClient* client,
                 ProfileOAuth2TokenService* token_service,
                 AccountTrackerService* account_tracker_service,