Remove obsolete class DownstreamChromiumBrowserProvider.

ios/chrome/browser/downstream_chromium_browser_provider.h

Index: ios/chrome/browser/downstream_chromium_browser_provider.h
diff --git a/ios/chrome/browser/downstream_chromium_browser_provider.h b/ios/chrome/browser/downstream_chromium_browser_provider.h
deleted file mode 100644
index acfadeb27168aea6aac246e3d15dbc161964852d..0000000000000000000000000000000000000000
--- a/ios/chrome/browser/downstream_chromium_browser_provider.h
+++ /dev/null
@@ -1,22 +0,0 @@
-// Copyright 2016 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.
-
-#ifndef IOS_CHROME_BROWSER_DOWNSTREAM_CHROMIUM_BROWSER_PROVIDER_H_
-#define IOS_CHROME_BROWSER_DOWNSTREAM_CHROMIUM_BROWSER_PROVIDER_H_
-
-#include "ios/chrome/browser/providers/chromium_browser_provider.h"
-
-// DownstreamChromiumBrowserProvider contains provider implementations that will
-// eventually move into the upstream ChromiumBrowserProvider, but currently
-// cannot move because they have internal dependencies.
-class DownstreamChromiumBrowserProvider : public ChromiumBrowserProvider {
- public:
-  DownstreamChromiumBrowserProvider();
-  ~DownstreamChromiumBrowserProvider() override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(DownstreamChromiumBrowserProvider);
-};
-
-#endif  // IOS_CHROME_BROWSER_DOWNSTREAM_CHROMIUM_BROWSER_PROVIDER_H_