First part to fix Bug 50726 "Save extension list and "winning" prefs from extensions"

chrome/browser/extensions/extension_prefs_unittest.cc

 // Copyright (c) 2010 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 "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/scoped_temp_dir.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
 #include "chrome/browser/browser_thread.h"
@@ skipping 349 matching lines @@
     EXPECT_EQ(launch_index + 1, new_launch_index);
 
     // This extension doesn't exist, so it should return -1.
     EXPECT_EQ(-1, prefs()->GetAppLaunchIndex("foo"));
   }
 
 private:
   scoped_refptr<Extension> extension_;
 };
 TEST_F(ExtensionPrefsAppLaunchIndex, ExtensionPrefsAppLaunchIndex) {}
+
+class ExtensionPrefsPrecedences : public ExtensionPrefsTest {
+ public:
+  virtual void Initialize() {
+    std::vector<std::string> precedence;
+    prefs()->GetExtensionPrecedences(&precedence);
+    EXPECT_EQ(0u, precedence.size());
+  }
+
+  virtual void Verify() {
+    std::vector<std::string> precedence;
+    precedence.push_back("A");
+    precedence.push_back("C");
+    precedence.push_back("B");
+    prefs()->PersistExtensionPrecedences(precedence);
+
+    prefs_.RecreateExtensionPrefs();
+
+    std::vector<std::string> retrieved_precedence;
+    prefs()->GetExtensionPrecedences(&retrieved_precedence);
+    EXPECT_EQ(precedence, retrieved_precedence);
+  }
+};
+TEST_F(ExtensionPrefsPrecedences, ExtensionPrefsPrecedences) {}
+