Reland: Stop passing raw pointers to base::Value API in c/b/chromeos and c/b/extensions

chrome/browser/extensions/api/proxy/proxy_api.h

Index: chrome/browser/extensions/api/proxy/proxy_api.h
diff --git a/chrome/browser/extensions/api/proxy/proxy_api.h b/chrome/browser/extensions/api/proxy/proxy_api.h
index f3c3fb5afe31f1ac0d7174b347dcab4346cfba58..d10fe758609b2f78cb14faeb042e7a2fb5098735 100644
--- a/chrome/browser/extensions/api/proxy/proxy_api.h
+++ b/chrome/browser/extensions/api/proxy/proxy_api.h
@@ -32,10 +32,12 @@ class ProxyPrefTransformer : public PrefTransformerInterface {
   ~ProxyPrefTransformer() override;
 
   // Implementation of PrefTransformerInterface.
-  base::Value* ExtensionToBrowserPref(const base::Value* extension_pref,
-                                      std::string* error,
-                                      bool* bad_message) override;
-  base::Value* BrowserToExtensionPref(const base::Value* browser_pref) override;
+  std::unique_ptr<base::Value> ExtensionToBrowserPref(
+      const base::Value* extension_pref,
+      std::string* error,
+      bool* bad_message) override;
+  std::unique_ptr<base::Value> BrowserToExtensionPref(
+      const base::Value* browser_pref) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ProxyPrefTransformer);