[Extensions] rm unnecessary GetRawDataResource().as_string() to reduce string copy.

chrome/browser/extensions/component_loader.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 "chrome/browser/extensions/component_loader.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/files/file_util.h"
@@ skipping 132 matching lines @@
   SCOPED_UMA_HISTOGRAM_TIMER("Extensions.LoadAllComponentTime");
 
   for (RegisteredComponentExtensions::iterator it =
           component_extensions_.begin();
       it != component_extensions_.end(); ++it) {
     Load(*it);
   }
 }
 
 base::DictionaryValue* ComponentLoader::ParseManifest(
-    const std::string& manifest_contents) const {
+    base::StringPiece manifest_contents) const {
   JSONStringValueDeserializer deserializer(manifest_contents);
   std::unique_ptr<base::Value> manifest = deserializer.Deserialize(NULL, NULL);
 
   if (!manifest.get() || !manifest->IsType(base::Value::TYPE_DICTIONARY)) {
     LOG(ERROR) << "Failed to parse extension manifest.";
     return NULL;
   }
   // Transfer ownership to the caller.
   return static_cast<base::DictionaryValue*>(manifest.release());
 }
 
 void ComponentLoader::ClearAllRegistered() {
   for (RegisteredComponentExtensions::iterator it =
           component_extensions_.begin();
       it != component_extensions_.end(); ++it) {
       delete it->manifest;
   }
 
   component_extensions_.clear();
 }
 
 std::string ComponentLoader::GetExtensionID(
     int manifest_resource_id,
     const base::FilePath& root_directory) {
-  std::string manifest_contents = ResourceBundle::GetSharedInstance().
-      GetRawDataResource(manifest_resource_id).as_string();
-  base::DictionaryValue* manifest = ParseManifest(manifest_contents);
+  base::DictionaryValue* manifest =
+      ParseManifest(ResourceBundle::GetSharedInstance().GetRawDataResource(
+          manifest_resource_id));
   if (!manifest)
     return std::string();
 
   ComponentExtensionInfo info(manifest, root_directory);
   return info.extension_id;
 }
 
 std::string ComponentLoader::Add(int manifest_resource_id,
                                  const base::FilePath& root_directory) {
   if (!ignore_whitelist_for_testing_ &&
@@ skipping 220 matching lines @@
 
 void ComponentLoader::AddWithNameAndDescription(
     int manifest_resource_id,
     const base::FilePath& root_directory,
     const std::string& name_string,
     const std::string& description_string) {
   if (!ignore_whitelist_for_testing_ &&
       !IsComponentExtensionWhitelisted(manifest_resource_id))
     return;
 
-  std::string manifest_contents =
+  base::StringPiece manifest_contents =
       ResourceBundle::GetSharedInstance().GetRawDataResource(
-          manifest_resource_id).as_string();
+          manifest_resource_id);
 
   // The Value is kept for the lifetime of the ComponentLoader. This is
   // required in case LoadAll() is called again.
   base::DictionaryValue* manifest = ParseManifest(manifest_contents);
 
   if (manifest) {
     manifest->SetString(manifest_keys::kName, name_string);
     manifest->SetString(manifest_keys::kDescription, description_string);
     Add(manifest, root_directory, true);
   }
@@ skipping 284 matching lines @@
       manifest.release(),
       root_directory,
       false);
   CHECK_EQ(extension_id, actual_extension_id);
   if (!done_cb.is_null())
     done_cb.Run();
 }
 #endif
 
 }  // namespace extensions