Remove ImageDataFetcher from iOS.

ios/web/public/test/mock_image_data_fetcher.mm

Index: ios/web/public/test/mock_image_data_fetcher.mm
diff --git a/ios/web/public/test/mock_image_data_fetcher.mm b/ios/web/public/test/mock_image_data_fetcher.mm
deleted file mode 100644
index fbdfd57bbaf9c7822374c0c38f63b2c24b07a6a7..0000000000000000000000000000000000000000
--- a/ios/web/public/test/mock_image_data_fetcher.mm
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 2015 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.
-
-#import "ios/web/public/test/mock_image_data_fetcher.h"
-
-namespace web {
-
-MockImageDataFetcher::MockImageDataFetcher(
-    const scoped_refptr<base::TaskRunner>& task_runner)
-    : ImageDataFetcher(task_runner) {}
-
-MockImageDataFetcher::~MockImageDataFetcher() {}
-
-}  // namespace web