Add an about:flag to support alternative data saver features

components/data_reduction_proxy/core/common/data_reduction_proxy_headers.cc

 // Copyright 2014 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.
 
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <string>
@@ skipping 28 matching lines @@
 
 // Previews directives.
 const char kEmptyImageDirective[] = "empty-image";
 const char kLitePageDirective[] = "lite-page";
 const char kCompressedVideoDirective[] = "compressed-video";
 const char kIdentityDirective[] = "identity";
 
 // The legacy Chrome-Proxy response header directive for LoFi images.
 const char kLegacyChromeProxyLoFiResponseDirective[] = "q=low";
 
-const char kChromeProxyLitePageIngoreBlacklistDirective[] =
-    "exp=ignore_preview_blacklist";
+const char kChromeProxyLitePageIngoreBlacklist[] = "ignore_preview_blacklist";
 
 const char kIfHeavyQualifier[] = "if-heavy";
 
 const char kChromeProxyActionBlockOnce[] = "block-once";
 const char kChromeProxyActionBlock[] = "block";
 const char kChromeProxyActionBypass[] = "bypass";
 
 // Actions for tamper detection fingerprints.
 const char kChromeProxyActionFingerprintChromeProxy[]   = "fcp";
 const char kChromeProxyActionFingerprintVia[]           = "fvia";
@@ skipping 87 matching lines @@
 }
 
 const char* compressed_video_directive() {
   return kCompressedVideoDirective;
 }
 
 const char* identity_directive() {
   return kIdentityDirective;
 }
 
-const char* chrome_proxy_lite_page_ignore_blacklist_directive() {
-  return kChromeProxyLitePageIngoreBlacklistDirective;
+const char* chrome_proxy_lite_page_ignore_blacklist() {
+  return kChromeProxyLitePageIngoreBlacklist;
 }
 
 const char* if_heavy_qualifier() {
   return kIfHeavyQualifier;
 }
 
 bool IsEmptyImagePreview(const net::HttpResponseHeaders& headers) {
   return IsPreviewType(headers, kEmptyImageDirective) ||
          headers.HasHeaderValue(kChromeProxyHeader,
                                 kLegacyChromeProxyLoFiResponseDirective);
@@ skipping 259 matching lines @@
   std::string value;
   size_t iter = 0;
   while (headers->EnumerateHeader(&iter, kChromeProxyHeader, &value)) {
     if (StartsWithActionPrefix(value, kChromeProxyActionFingerprintChromeProxy))
       continue;
     values->push_back(std::move(value));
   }
 }
 
 }  // namespace data_reduction_proxy