Remove explicit keyword from multi-argument constructors

chrome/service/cloud_print/cloud_print_proxy_backend.cc

Index: chrome/service/cloud_print/cloud_print_proxy_backend.cc
diff --git a/chrome/service/cloud_print/cloud_print_proxy_backend.cc b/chrome/service/cloud_print/cloud_print_proxy_backend.cc
index 7e6b3b17de20a3ef3eb7efb30b426945bbaf7fba..f76c2ce44cfef300fbc30347d16d76ce2bb621a9 100644
--- a/chrome/service/cloud_print/cloud_print_proxy_backend.cc
+++ b/chrome/service/cloud_print/cloud_print_proxy_backend.cc
@@ -44,11 +44,11 @@ class CloudPrintProxyBackend::Core
  public:
   // It is OK for print_server_url to be empty. In this case system should
   // use system default (local) print server.
-  explicit Core(CloudPrintProxyBackend* backend,
-                const GURL& cloud_print_server_url,
-                const DictionaryValue* print_system_settings,
-                const gaia::OAuthClientInfo& oauth_client_info,
-                bool enable_job_poll);
+  Core(CloudPrintProxyBackend* backend,
+       const GURL& cloud_print_server_url,
+       const DictionaryValue* print_system_settings,
+       const gaia::OAuthClientInfo& oauth_client_info,
+       bool enable_job_poll);
 
   // Note:
   //