[Extensions] Break up BaseFeatureProvider, create JSONFeatureProvider

extensions/common/features/base_feature_provider.cc

Index: extensions/common/features/base_feature_provider.cc
diff --git a/extensions/common/features/base_feature_provider.cc b/extensions/common/features/base_feature_provider.cc
index 40065ff01fece213028bf1cc832ba13efb9bc8b4..99b8bb423edd573b5ea84568cc09017c712c64f7 100644
--- a/extensions/common/features/base_feature_provider.cc
+++ b/extensions/common/features/base_feature_provider.cc
@@ -4,148 +4,14 @@
 
 #include "extensions/common/features/base_feature_provider.h"
 
-#include <stddef.h>
-
-#include <stack>
-#include <utility>
-
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
-#include "base/values.h"
-#include "extensions/common/extensions_client.h"
-#include "extensions/common/features/complex_feature.h"
-#include "extensions/common/features/simple_feature.h"
+#include "extensions/common/features/feature.h"
 
 namespace extensions {
 
-namespace {
-
-bool IsNocompile(const base::Value& value) {
-  bool nocompile = false;
-  const base::DictionaryValue* as_dict = nullptr;
-  if (value.GetAsDictionary(&as_dict)) {
-    as_dict->GetBoolean("nocompile", &nocompile);
-  } else {
-    // "nocompile" is not supported for any other feature type.
-  }
-  return nocompile;
-}
-
-bool ParseFeature(const base::DictionaryValue* value,
-                  const std::string& name,
-                  SimpleFeature* feature) {
-  feature->set_name(name);
-  std::string error = feature->Parse(value);
-  if (!error.empty())
-    LOG(ERROR) << error;
-  return error.empty();
-}
-
-}  // namespace
-
-BaseFeatureProvider::BaseFeatureProvider(const base::DictionaryValue& root,
-                                         FeatureFactory factory)
-    : factory_(factory) {
-  for (base::DictionaryValue::Iterator iter(root); !iter.IsAtEnd();
-       iter.Advance()) {
-    if (IsNocompile(iter.value())) {
-      continue;
-    }
-
-    if (iter.value().GetType() == base::Value::TYPE_DICTIONARY) {
-      std::unique_ptr<SimpleFeature> feature((*factory_)());
-
-      std::vector<std::string> split = base::SplitString(
-          iter.key(), ".", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
-
-      // Push parent features on the stack, starting with the current feature.
-      // If one of the features has "noparent" set, stop pushing features on
-      // the stack. The features will then be parsed in order, starting with
-      // the farthest parent that is either top level or has "noparent" set.
-      std::stack<std::pair<std::string, const base::DictionaryValue*> >
-          parse_stack;
-      while (!split.empty()) {
-        std::string parent_name = base::JoinString(split, ".");
-        split.pop_back();
-        if (root.HasKey(parent_name)) {
-          const base::DictionaryValue* parent = nullptr;
-          if (!root.GetDictionaryWithoutPathExpansion(parent_name, &parent)) {
-            // If the parent is a complex feature, find the parent with the
-            // 'default_parent' flag.
-            const base::ListValue* parent_list = nullptr;
-            CHECK(root.GetListWithoutPathExpansion(parent_name, &parent_list));
-            for (size_t i = 0; i < parent_list->GetSize(); ++i) {
-              CHECK(parent_list->GetDictionary(i, &parent));
-              if (parent->HasKey("default_parent"))
-                break;
-              parent = nullptr;
-            }
-            CHECK(parent) << parent_name << " must declare one of its features"
-                << " the default parent, with {\"default_parent\": true}.";
-          }
-          parse_stack.push(std::make_pair(parent_name, parent));
-          bool no_parent = false;
-          parent->GetBoolean("noparent", &no_parent);
-          if (no_parent)
-            break;
-        }
-      }
-
-      CHECK(!parse_stack.empty());
-      // Parse all parent features.
-      bool parse_error = false;
-      while (!parse_stack.empty()) {
-        if (!ParseFeature(parse_stack.top().second,
-                          parse_stack.top().first,
-                          feature.get())) {
-          parse_error = true;
-          break;
-        }
-        parse_stack.pop();
-      }
-
-      if (parse_error)
-        continue;
-
-      features_[iter.key()] = std::move(feature);
-    } else if (iter.value().GetType() == base::Value::TYPE_LIST) {
-      // This is a complex feature.
-      const base::ListValue* list =
-          static_cast<const base::ListValue*>(&iter.value());
-      CHECK_GT(list->GetSize(), 0UL);
-
-      std::unique_ptr<ComplexFeature::FeatureList> features(
-          new ComplexFeature::FeatureList());
-
-      // Parse and add all SimpleFeatures from the list.
-      for (const auto& entry : *list) {
-        base::DictionaryValue* dict;
-        if (!entry->GetAsDictionary(&dict)) {
-          LOG(ERROR) << iter.key() << ": Feature rules must be dictionaries.";
-          continue;
-        }
-
-        std::unique_ptr<SimpleFeature> feature((*factory_)());
-        if (!ParseFeature(dict, iter.key(), feature.get()))
-          continue;
-
-        features->push_back(std::move(feature));
-      }
-
-      std::unique_ptr<ComplexFeature> feature(
-          new ComplexFeature(std::move(features)));
-      feature->set_name(iter.key());
-
-      features_[iter.key()] = std::move(feature);
-    } else {
-      LOG(ERROR) << iter.key() << ": Feature description must be dictionary or"
-                 << " list of dictionaries.";
-    }
-  }
-}
-
-BaseFeatureProvider::~BaseFeatureProvider() {
-}
+BaseFeatureProvider::BaseFeatureProvider() {}
+BaseFeatureProvider::~BaseFeatureProvider() {}
 
 const FeatureMap& BaseFeatureProvider::GetAllFeatures() const {
   return features_;