predictors: Remove unknown fields from PrecacheManifest before store it.

chrome/browser/predictors/resource_prefetch_predictor.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 "chrome/browser/predictors/resource_prefetch_predictor.h"
 
 #include <map>
 #include <set>
 #include <utility>
 
@@ skipping 203 matching lines @@
       precision_percentage);
   UMA_HISTOGRAM_PERCENTAGE(internal::kResourcePrefetchPredictorRecallHistogram,
                            recall_percentage);
   UMA_HISTOGRAM_COUNTS_100(internal::kResourcePrefetchPredictorCountHistogram,
                            predicted_urls.size());
   UMA_HISTOGRAM_ENUMERATION(
       internal::kResourcePrefetchPredictorRedirectStatusHistogram,
       static_cast<int>(redirect_status), static_cast<int>(RedirectStatus::MAX));
 }
 
+void RemoveUnknownFieldsFromPrecacheManifest(
+    precache::PrecacheManifest* manifest) {
+  manifest->mutable_unknown_fields()->clear();
+  for (auto& resource : *manifest->mutable_resource())
+    resource.mutable_unknown_fields()->clear();
+  if (manifest->has_experiments()) {
+    manifest->mutable_experiments()->mutable_unknown_fields()->clear();
+    for (auto& kv : *manifest->mutable_experiments()
+                         ->mutable_resources_by_experiment_group()) {
+      kv.second.mutable_unknown_fields()->clear();
+    }
+  }
+  if (manifest->has_id())
+    manifest->mutable_id()->mutable_unknown_fields()->clear();
+}
+
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // ResourcePrefetchPredictor static functions.
 
 // static
 bool ResourcePrefetchPredictor::ShouldRecordRequest(
     net::URLRequest* request,
     content::ResourceType resource_type) {
   const content::ResourceRequestInfo* request_info =
@@ skipping 1225 matching lines @@
   auto cache_entry = manifest_table_cache_->find(host);
   if (cache_entry == manifest_table_cache_->end()) {
     if (manifest_table_cache_->size() >= config_.max_hosts_to_track)
       RemoveOldestEntryInManifestDataMap(manifest_table_cache_.get());
     cache_entry =
         manifest_table_cache_->insert(std::make_pair(host, manifest)).first;
   } else {
     cache_entry->second = manifest;
   }
 
+  RemoveUnknownFieldsFromPrecacheManifest(&cache_entry->second);
+
   BrowserThread::PostTask(
       BrowserThread::DB, FROM_HERE,
       base::Bind(&ResourcePrefetchPredictorTables::UpdateManifestData, tables_,
                  host, cache_entry->second));
 }
 
 void ResourcePrefetchPredictor::ConnectToHistoryService() {
   // Register for HistoryServiceLoading if it is not ready.
   history::HistoryService* history_service =
       HistoryServiceFactory::GetForProfile(profile_,
@@ skipping 14 matching lines @@
 TestObserver::~TestObserver() {
   predictor_->SetObserverForTesting(nullptr);
 }
 
 TestObserver::TestObserver(ResourcePrefetchPredictor* predictor)
     : predictor_(predictor) {
   predictor_->SetObserverForTesting(this);
 }
 
 }  // namespace predictors