Update SplitString calls in components

components/variations/net/variations_http_header_provider.cc

Index: components/variations/net/variations_http_header_provider.cc
diff --git a/components/variations/net/variations_http_header_provider.cc b/components/variations/net/variations_http_header_provider.cc
index f94ad2c953a126c38368cb6195b860ae94a7e988..9f86ea0417386a42ec0918fb5bfbd271b7c22a8b 100644
--- a/components/variations/net/variations_http_header_provider.cc
+++ b/components/variations/net/variations_http_header_provider.cc
@@ -88,21 +88,20 @@ bool VariationsHttpHeaderProvider::SetDefaultVariationIds(
     const std::string& variation_ids) {
   default_variation_ids_set_.clear();
   default_trigger_id_set_.clear();
-  std::vector<std::string> entries;
-  base::SplitString(variation_ids, ',', &entries);
-  for (std::vector<std::string>::const_iterator it = entries.begin();
-       it != entries.end(); ++it) {
-    if (it->empty()) {
+  for (const base::StringPiece& entry : base::SplitStringPiece(
+           variation_ids, ",", base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL)) {
+    if (entry.empty()) {
       default_variation_ids_set_.clear();
       default_trigger_id_set_.clear();
       return false;
     }
-    bool trigger_id = base::StartsWith(*it, "t", base::CompareCase::SENSITIVE);
+    bool trigger_id =
+        base::StartsWith(entry, "t", base::CompareCase::SENSITIVE);
     // Remove the "t" prefix if it's there.
-    std::string entry = trigger_id ? it->substr(1) : *it;
+    base::StringPiece trimmed_entry = trigger_id ?  entry.substr(1) : entry;
 
     int variation_id = 0;
-    if (!base::StringToInt(entry, &variation_id)) {
+    if (!base::StringToInt(trimmed_entry, &variation_id)) {
       default_variation_ids_set_.clear();
       default_trigger_id_set_.clear();
       return false;