Cleanup some PPAPI proxy code.

ppapi/proxy/flash_font_file_resource.cc

 // Copyright (c) 2012 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 "ppapi/proxy/flash_font_file_resource.h"
 
 #include <cstring>
 
 #include "ppapi/c/dev/ppb_font_dev.h"
 #include "ppapi/c/pp_errors.h"
@@ skipping 24 matching lines @@
                                             void* output,
                                             uint32_t* output_length) {
   if (!output_length)
     return PP_FALSE;
 
   if (!sent_create_to_renderer()) {
     SendCreate(
         RENDERER, PpapiHostMsg_FlashFontFile_Create(description_, charset_));
   }
 
-  std::string* contents = GetFontTable(table);
+  const std::string* contents = GetFontTable(table);
   if (!contents) {
     std::string out_contents;
     int32_t result = SyncCall<PpapiPluginMsg_FlashFontFile_GetFontTableReply>(
         RENDERER, PpapiHostMsg_FlashFontFile_GetFontTable(table),
         &out_contents);
     if (result != PP_OK)
       return PP_FALSE;
 
     contents = AddFontTable(table, out_contents);
   }
 
   // If we are going to copy the data into |output|, it must be big enough.
   if (output && *output_length < contents->size())
     return PP_FALSE;
 
   *output_length = static_cast<uint32_t>(contents->size());
   if (output)
     memcpy(output, contents->c_str(), *output_length);
   return PP_TRUE;
 }
 
-std::string* FlashFontFileResource::GetFontTable(uint32_t table) const {
+const std::string* FlashFontFileResource::GetFontTable(uint32_t table) const {
   FontTableMap::const_iterator found = font_tables_.find(table);
-  if (found == font_tables_.end())
-    return NULL;
-  return found->second.get();
+  return (found != font_tables_.end()) ? found->second : nullptr;
 }
 
-std::string* FlashFontFileResource::AddFontTable(uint32_t table,
-                                                 const std::string& contents) {
-  linked_ptr<std::string> heap_string(new std::string(contents));
-  font_tables_[table] = heap_string;
-  return heap_string.get();
+const std::string* FlashFontFileResource::AddFontTable(
+    uint32_t table,
+    const std::string& contents) {
+  FontTableMap::const_iterator it =
+      font_tables_.set(table, make_scoped_ptr(new std::string(contents)));
+  return it->second;
 }
 
 }  // namespace proxy
 }  // namespace ppapi