Add a cache counter for iOS.

ios/chrome/browser/browsing_data/ios_browsing_data_counter_factory.cc

Index: ios/chrome/browser/browsing_data/ios_browsing_data_counter_factory.cc
diff --git a/ios/chrome/browser/browsing_data/ios_browsing_data_counter_factory.cc b/ios/chrome/browser/browsing_data/ios_browsing_data_counter_factory.cc
index 1603efc68902da9959a6c7c8a30fe85de9ae22cb..470ed15e0fa7d736b9c986de9e089d5d7cb85b44 100644
--- a/ios/chrome/browser/browsing_data/ios_browsing_data_counter_factory.cc
+++ b/ios/chrome/browser/browsing_data/ios_browsing_data_counter_factory.cc
@@ -15,6 +15,7 @@
 #include "components/browsing_data/core/pref_names.h"
 #include "components/keyed_service/core/service_access_type.h"
 #include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/browsing_data/cache_counter.h"
 #include "ios/chrome/browser/experimental_flags.h"
 #include "ios/chrome/browser/history/history_service_factory.h"
 #include "ios/chrome/browser/history/web_history_service_factory.h"
@@ -39,6 +40,9 @@ IOSBrowsingDataCounterFactory::GetForBrowserStateAndPref(
         IOSChromeProfileSyncServiceFactory::GetForBrowserState(browser_state));
   }
 
+  if (pref_name == browsing_data::prefs::kDeleteCache)
+    return base::MakeUnique<CacheCounter>(browser_state);
+
   if (pref_name == browsing_data::prefs::kDeletePasswords) {
     return base::MakeUnique<browsing_data::PasswordsCounter>(
         IOSChromePasswordStoreFactory::GetForBrowserState(