Split ExtensionSystem interface from ExtensionSystemImpl implementation, part 1.

chrome/browser/extensions/browsertest_util.cc

 // Copyright 2013 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/browsertest_util.h"
 
 #include "chrome/browser/extensions/extension_host.h"
-#include "chrome/browser/extensions/extension_system.h"
+#include "chrome/browser/profiles/profile.h"
 #include "content/public/test/browser_test_utils.h"
+#include "extensions/browser/extension_system.h"
 #include "extensions/browser/process_manager.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace extensions {
 namespace browsertest_util {
 
 std::string ExecuteScriptInBackgroundPage(Profile* profile,
                                           const std::string& extension_id,
                                           const std::string& script) {
   extensions::ProcessManager* manager =
       extensions::ExtensionSystem::Get(profile)->process_manager();
   extensions::ExtensionHost* host =
       manager->GetBackgroundHostForExtension(extension_id);
   if (host == NULL) {
     ADD_FAILURE() << "Extension " << extension_id << " has no background page.";
     return "";
   }
   std::string result;
   if (!content::ExecuteScriptAndExtractString(
            host->host_contents(), script, &result)) {
     ADD_FAILURE() << "Executing script failed: " << script;
     result.clear();
   }
   return result;
 }
 
 }  // namespace browsertest_util
 }  // namespace extensions