Introduce ServiceWorkerCache.Response.HasDeprecatedURL UMA

content/browser/cache_storage/cache_storage_cache.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 "content/browser/cache_storage/cache_storage_cache.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <limits>
 #include <memory>
@@ skipping 1385 matching lines @@
     DCHECK_EQ(std::string::npos, header.value().find('\0'));
     request->headers.insert(std::make_pair(header.name(), header.value()));
   }
 }
 
 void CacheStorageCache::PopulateResponseMetadata(
     const proto::CacheMetadata& metadata,
     ServiceWorkerResponse* response) {
   std::unique_ptr<std::vector<GURL>> url_list =
       base::MakeUnique<std::vector<GURL>>();
-  // TODO(horo) Add UMA for the deprecated URL field.
+  // From Chrome 57, proto::CacheMetadata's url field was deprecated.
+  UMA_HISTOGRAM_BOOLEAN("ServiceWorkerCache.Response.HasDeprecatedURL",
+                        metadata.response().has_url());
   if (metadata.response().has_url()) {
     url_list->push_back(GURL(metadata.response().url()));
   } else {
     url_list->reserve(metadata.response().url_list_size());
     for (int i = 0; i < metadata.response().url_list_size(); ++i)
       url_list->push_back(GURL(metadata.response().url_list(i)));
   }
 
   std::unique_ptr<ServiceWorkerHeaderMap> headers =
       base::MakeUnique<ServiceWorkerHeaderMap>();
@@ skipping 33 matching lines @@
       temp_entry, INDEX_RESPONSE_BODY, INDEX_SIDE_DATA);
   return blob_storage_context_->AddFinishedBlob(&blob_data);
 }
 
 std::unique_ptr<CacheStorageCacheHandle>
 CacheStorageCache::CreateCacheHandle() {
   return cache_storage_->CreateCacheHandle(this);
 }
 
 }  // namespace content