Remove a bunch of DeepCopy() calls in the chrome.storage API.

chrome/browser/extensions/api/storage/setting_sync_data.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTING_SYNC_DATA_H_
 #define CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTING_SYNC_DATA_H_
 
-#include "base/memory/ref_counted.h"
+#include <string>
+
+#include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
 #include "base/values.h"
 #include "sync/api/sync_change.h"
 
 namespace syncer {
 class SyncData;
 }
 
 namespace sync_pb {
 class ExtensionSettingSpecifics;
 }
@@ skipping 12 matching lines @@
 
   // Creates explicitly.
   SettingSyncData(
       syncer::SyncChange::SyncChangeType change_type,
       const std::string& extension_id,
       const std::string& key,
       scoped_ptr<base::Value> value);
 
   ~SettingSyncData();
 
   // Returns the type of the sync change; may be ACTION_INVALID.

[Devlin, 2015/05/19 15:41:55]

nit: We almost never document simple accessors.  Most of these comments, if
they're not totally silly ("Returns the settings key" is pretty silly) should be
moved to the member variable.  If you feel up for the move, please do,
otherwise, whatevs.

[not at google - send to devlin, 2015/05/19 19:43:58]

This comment serves a purpose.

-  syncer::SyncChange::SyncChangeType change_type() const;
+  syncer::SyncChange::SyncChangeType change_type() const {
+    return change_type_;
+  }
 
   // Returns the extension id the setting is for.

[not at google - send to devlin, 2015/05/19 19:43:58]

this does not

-  const std::string& extension_id() const;
+  const std::string& extension_id() const { return extension_id_; }
 
   // Returns the settings key.

[not at google - send to devlin, 2015/05/19 19:43:58]

nor does this

-  const std::string& key() const;
+  const std::string& key() const { return key_; }
 
-  // Returns the value of the setting.
-  const base::Value& value() const;
+  // Returns the value of the setting. Cannot be called if PassValue() has been
+  // called.

[not at google - send to devlin, 2015/05/19 19:43:57]

this does.

+  const base::Value& value() const { return *value_; }
+
+  // Releases ownership of the value to the caller.

[not at google - send to devlin, 2015/05/19 19:43:58]

I should improve this comment because it's important to say that neither
PassValue() nor value() can be called from this point onwards.

with that in mind, it's visually consistent to document every accessor, but I
can remove them anyway.

+  scoped_ptr<base::Value> PassValue();
 
  private:
-  // Ref-counted container for the data.
-  // TODO(kalman): Use browser_sync::Immutable<Internal>.
-  class Internal : public base::RefCountedThreadSafe<Internal> {
-   public:
-    Internal(
-      syncer::SyncChange::SyncChangeType change_type,
-      const std::string& extension_id,
-      const std::string& key,
-      scoped_ptr<base::Value> value);
+  // Populates the extension ID, key, and value from |sync_data|. This will be
+  // either an extension or app settings data type.
+  void Init(const syncer::SyncData& sync_data);
 
-    syncer::SyncChange::SyncChangeType change_type_;
-    std::string extension_id_;
-    std::string key_;
-    scoped_ptr<base::Value> value_;
+  syncer::SyncChange::SyncChangeType change_type_;
+  std::string extension_id_;
+  std::string key_;
+  scoped_ptr<base::Value> value_;
 
-   private:
-    friend class base::RefCountedThreadSafe<Internal>;
-    ~Internal();
-  };
-
-  // Initializes internal_ from sync data for an extension or app setting.
-  void Init(syncer::SyncChange::SyncChangeType change_type,
-            const syncer::SyncData& sync_data);
-
-  // Initializes internal_ from extension specifics.
-  void InitFromExtensionSettingSpecifics(
-      syncer::SyncChange::SyncChangeType change_type,
-      const sync_pb::ExtensionSettingSpecifics& specifics);
-
-  scoped_refptr<Internal> internal_;
+  DISALLOW_COPY_AND_ASSIGN(SettingSyncData);

[Devlin, 2015/05/15 23:58:18]

Woo!

 };
 
-typedef std::vector<SettingSyncData> SettingSyncDataList;
+typedef ScopedVector<SettingSyncData> SettingSyncDataList;
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_STORAGE_SETTING_SYNC_DATA_H_