Allow manifest handlers to declare keys they depend on that must be parsed before them.

chrome/common/extensions/manifest_tests/extension_manifest_test.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/common/extensions/manifest_tests/extension_manifest_test.h"
 
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/values.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/path_service.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/extension_l10n_util.h"
+#include "chrome/common/extensions/manifest_handler.h"
 #include "ui/base/l10n/l10n_util.h"
 
 using extensions::Extension;
 
 ExtensionManifestTest::ExtensionManifestTest()
     : enable_apps_(true),
       // UNKNOWN == trunk.
       current_channel_(chrome::VersionInfo::CHANNEL_UNKNOWN) {}
 
+void ExtensionManifestTest::SetUp() {
+  extensions::ManifestHandler::ClearRegistryForTesting();
+}
+
 // static
 DictionaryValue* ExtensionManifestTest::LoadManifestFile(
     const std::string& filename,
     std::string* error) {
   FilePath filename_path(FilePath::FromUTF8Unsafe(filename));
   FilePath extension_path;
   FilePath manifest_path;
 
   if (filename_path.IsAbsolute()) {
     extension_path = filename_path.DirName();
@@ skipping 205 matching lines @@
       break;
     case EXPECT_TYPE_SUCCESS:
       for (size_t i = 0; i < num_testcases; ++i) {
         LoadAndExpectSuccess(testcases[i].manifest_filename_.c_str(),
                              testcases[i].location_,
                              testcases[i].flags_);
       }
       break;
    }
 }