Implement ComplexFeature to support permission features with multiple rules.

chrome/common/extensions/manifest_unittest.cc

Index: chrome/common/extensions/manifest_unittest.cc
diff --git a/chrome/common/extensions/manifest_unittest.cc b/chrome/common/extensions/manifest_unittest.cc
index c0030b6bebbff2529c9c25b34ca8f4680253fc88..f0ddf73fa6fbf8d6e74f47e1aa50573005c4d155 100644
--- a/chrome/common/extensions/manifest_unittest.cc
+++ b/chrome/common/extensions/manifest_unittest.cc
@@ -13,6 +13,7 @@
 #include "base/values.h"
 #include "chrome/common/extensions/extension_manifest_constants.h"
 #include "chrome/common/extensions/features/feature.h"
+#include "chrome/common/extensions/features/simple_feature.h"
 #include "extensions/common/error_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -94,7 +95,7 @@ TEST_F(ManifestTest, Extension) {
   EXPECT_TRUE(error.empty());
   ASSERT_EQ(2u, warnings.size());
   {
-    Feature feature;
+    SimpleFeature feature;
     feature.set_name("background_page");
     feature.set_max_manifest_version(1);
     EXPECT_EQ(