Add SpdyString alias for std::string in net/spdy.

net/spdy/spdy_header_indexing.cc

 // Copyright (c) 2016 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 "net/spdy/spdy_header_indexing.h"
 
 #include "net/spdy/spdy_bug_tracker.h"
 
 namespace net {
 
 int32_t FLAGS_gfe_spdy_indexing_set_bound = 50;
 int32_t FLAGS_gfe_spdy_tracking_set_bound = 1000;
 
 HeaderIndexing::HeaderIndexing()
     : indexing_set_bound_(FLAGS_gfe_spdy_indexing_set_bound),
       tracking_set_bound_(FLAGS_gfe_spdy_tracking_set_bound) {
   SPDY_BUG_IF(indexing_set_bound_ >= tracking_set_bound_)
       << "Tracking set should be larger than indexing set";
 }
 
 HeaderIndexing::~HeaderIndexing() {}
 
 void HeaderIndexing::CreateInitIndexingHeaders() {
-  const std::string initial_fields[] = {
+  const SpdyString initial_fields[] = {
       // Estimated top 100 fields.
       "alt-svc",
       "date",
       "cache-control",
       "content-type",
       "expires",
       "location",
       "x-xss-protection",
       "p3p",
       "set-cookie",
@@ skipping 97 matching lines @@
       HeaderSet(initial_fields, initial_fields + arraysize(initial_fields));
 }
 
 bool HeaderIndexing::ShouldIndex(SpdyStringPiece header,
                                  SpdyStringPiece /* value */) {
   total_header_count_++;
   if (header.empty()) {
     return false;
   }
   // header is in indexing set.
-  std::string header_str(header.data(), header.size());
+  SpdyString header_str(header.data(), header.size());
   if (indexing_set_.find(header_str) != indexing_set_.end()) {
     return true;
   }
   // header not in indexing set. Check tracking set.
   if (tracking_set_.find(header_str) != tracking_set_.end()) {
     // Seen this header before. Add it to indexing set.
     TryInsertHeader(std::move(header_str), &indexing_set_, indexing_set_bound_);
     missed_header_in_tracking_++;
   } else {
     // Add header to tracking set.
     TryInsertHeader(std::move(header_str), &tracking_set_, tracking_set_bound_);
     missed_header_in_indexing_++;
   }
   return false;
 }
 
-void HeaderIndexing::TryInsertHeader(std::string&& header,
+void HeaderIndexing::TryInsertHeader(SpdyString&& header,
                                      HeaderSet* set,
                                      size_t bound) {
   std::pair<HeaderSet::iterator, bool> result = set->insert(std::move(header));
   if (set->size() > bound) {
     // Reach the size limit. Remove the header next to the newly added header.
     // If the new header is at the end, look for the "next" element at the
     // beginning.
     HeaderSet::iterator it = std::next(result.first);
     if (it != set->end()) {
       set->erase(it);
     } else {
       set->erase(set->begin());
     }
   }
 }
 
 }  // namespace net