Move the rest of extension_manifest_constants to top-level extensions/

chrome/common/extensions/manifest_tests/extension_manifests_homepage_unittest.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/extension.h"
-#include "chrome/common/extensions/extension_manifest_constants.h"
 #include "chrome/common/extensions/manifest_tests/extension_manifest_test.h"
 #include "chrome/common/extensions/manifest_url_handler.h"
+#include "extensions/common/manifest_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/base/l10n/l10n_util.h"
 
-namespace errors = extension_manifest_errors;
+namespace errors = extensions::manifest_errors;
 
 class HomepageURLManifestTest : public ExtensionManifestTest {
 };
 
 TEST_F(HomepageURLManifestTest, ParseHomepageURLs) {
   scoped_refptr<extensions::Extension> extension(
       LoadAndExpectSuccess("homepage_valid.json"));
 
   Testcase testcases[] = {
     Testcase("homepage_empty.json",
@@ skipping 17 matching lines @@
   // can be different in testing, so we just check the part before id.
   extension = LoadAndExpectSuccess("homepage_google_hosted.json");
   EXPECT_TRUE(StartsWithASCII(
       extensions::ManifestURL::GetHomepageURL(extension.get()).spec(),
       "https://chrome.google.com/webstore/detail/",
       false));
 
   extension = LoadAndExpectSuccess("homepage_externally_hosted.json");
   EXPECT_EQ(GURL(), extensions::ManifestURL::GetHomepageURL(extension.get()));
 }