[Extensions Bindings] Add ChromeSetting custom type

extensions/renderer/chrome_setting.cc

Index: extensions/renderer/chrome_setting.cc
diff --git a/extensions/renderer/chrome_setting.cc b/extensions/renderer/chrome_setting.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c32c094245b6f58e00dd120be245938a38ff715d
--- /dev/null
+++ b/extensions/renderer/chrome_setting.cc
@@ -0,0 +1,182 @@
+// Copyright 2017 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 "extensions/renderer/chrome_setting.h"
+
+#include "base/memory/ptr_util.h"
+#include "base/strings/stringprintf.h"
+#include "base/values.h"
+#include "extensions/renderer/api_custom_types.h"
+#include "extensions/renderer/api_event_handler.h"
+#include "extensions/renderer/api_request_handler.h"
+#include "extensions/renderer/api_signature.h"
+#include "gin/arguments.h"
+#include "gin/handle.h"
+#include "gin/object_template_builder.h"
+
+namespace extensions {
+
+v8::Local<v8::Object> ChromeSetting::CreateChromeSetting(
+    v8::Local<v8::Context> context,
+    const std::string& property_name,
+    APIRequestHandler* request_handler,
+    APIEventHandler* event_handler,
+    APITypeReferenceMap* type_refs) {
+  auto value_spec = base::MakeUnique<base::DictionaryValue>();
+  // Most ChromeSettings have a pref that matches the property name and are of
+  // type boolean.
+  std::string pref_name = property_name;

[jbroman, 2017/02/24 18:08:45]

super-nit: This and the few beneath it could even just be base::StringPiece
(which saves a couple string copies). Don't feel strongly, but noticed that
DictionaryValue::SetString does take StringPiece.

[Devlin, 2017/02/24 20:12:28]

Done.

+  std::string type = "boolean";
+
+  // A few of ChromeSettings are special, and have different arguments.
+  std::string ref;
+  if (property_name == "animationPolicy") {
+    type = "string";
+    auto enum_list = base::MakeUnique<base::ListValue>();
+    enum_list->AppendString("allowed");
+    enum_list->AppendString("once");
+    enum_list->AppendString("none");
+    value_spec->Set("enum", std::move(enum_list));
+  } else if (property_name == "webRTCIPHandlingPolicy") {
+    ref = "IPHandlingPolicy";
+  } else if (property_name == "spdyProxyEnabled") {
+    pref_name = "spdy_proxy.enabled";
+  } else if (property_name == "dataReductionDailyContentLength") {
+    type = "array";
+    pref_name = "data_reduction.daily_original_length";
+  } else if (property_name == "dataReductionDailyReceivedLength") {
+    type = "array";
+    pref_name = "data_reduction.daily_received_length";
+  } else if (property_name == "dataUsageReportingEnabled") {
+    pref_name = "data_usage_reporting.enabled";
+  } else if (property_name == "proxy") {
+    ref = "ProxyConfig";
+  }
+
+  if (!ref.empty())
+    value_spec->SetString("$ref", ref);
+  else
+    value_spec->SetString("type", type);
+
+  // The set() call takes an object { value: { type: <t> }, ... }, where <t>
+  // is the custom set() argument specified above by value_spec.
+  base::DictionaryValue set_spec;
+  set_spec.SetString("type", "object");
+  auto properties = base::MakeUnique<base::DictionaryValue>();
+  properties->Set("value", std::move(value_spec));
+  set_spec.Set("properties", std::move(properties));
+
+  gin::Handle<ChromeSetting> handle =
+      gin::CreateHandle(context->GetIsolate(),
+                        new ChromeSetting(request_handler, event_handler,
+                                          type_refs, pref_name, set_spec));
+  return handle.ToV8().As<v8::Object>();
+}
+
+ChromeSetting::ChromeSetting(APIRequestHandler* request_handler,
+                             APIEventHandler* event_handler,
+                             const APITypeReferenceMap* type_refs,
+                             const std::string& pref_name,
+                             const base::DictionaryValue& argument_spec)
+    : request_handler_(request_handler),
+      event_handler_(event_handler),
+      type_refs_(type_refs),
+      pref_name_(pref_name),
+      argument_spec_(argument_spec) {}
+
+ChromeSetting::~ChromeSetting() = default;
+
+gin::WrapperInfo ChromeSetting::kWrapperInfo = {gin::kEmbedderNativeGin};
+
+gin::ObjectTemplateBuilder ChromeSetting::GetObjectTemplateBuilder(
+    v8::Isolate* isolate) {
+  return Wrappable<ChromeSetting>::GetObjectTemplateBuilder(isolate)
+      .SetMethod("get", &ChromeSetting::Get)
+      .SetMethod("set", &ChromeSetting::Set)
+      .SetMethod("clear", &ChromeSetting::Clear)
+      .SetProperty("onChange", &ChromeSetting::GetOnChangeEvent);
+}
+
+void ChromeSetting::Get(gin::Arguments* arguments) {
+  HandleFunction("get", arguments);
+}
+
+void ChromeSetting::Set(gin::Arguments* arguments) {
+  v8::Isolate* isolate = arguments->isolate();
+  v8::HandleScope handle_scope(isolate);
+
+  v8::Local<v8::Object> holder;
+  CHECK(arguments->GetHolder(&holder));
+  v8::Local<v8::Context> context = holder->CreationContext();
+
+  v8::Local<v8::Value> value = arguments->PeekNext();
+  // The set schema included in the Schema object is generic, since it varies
+  // per-setting. However, this is only ever for a single setting, so we can
+  // enforce the types more thoroughly.
+  std::string error;
+  if (!value.IsEmpty() &&
+      !argument_spec_.ParseArgument(context, value, *type_refs_, nullptr,
+                                    &error)) {
+    arguments->ThrowTypeError("Invalid invocation");
+    return;
+  }
+  HandleFunction("set", arguments);
+}
+
+void ChromeSetting::Clear(gin::Arguments* arguments) {
+  HandleFunction("clear", arguments);
+}
+
+v8::Local<v8::Value> ChromeSetting::GetOnChangeEvent(
+    gin::Arguments* arguments) {
+  v8::Local<v8::Value> event;
+  if (event_.IsEmpty()) {
+    v8::Local<v8::Object> holder;
+    CHECK(arguments->GetHolder(&holder));
+    v8::Local<v8::Context> context = holder->CreationContext();
+
+    event = event_handler_->CreateEventInstance(
+        base::StringPrintf("types.ChromeSetting.%s.onChange",
+                           pref_name_.c_str()),
+        context);
+    event_.Reset(arguments->isolate(), event);
+  } else {
+    event = event_.Get(arguments->isolate());
+  }
+  return event;
+}
+
+void ChromeSetting::HandleFunction(const std::string& method_name,
+                                   gin::Arguments* arguments) {
+  v8::Isolate* isolate = arguments->isolate();
+  v8::HandleScope handle_scope(isolate);
+  v8::Local<v8::Object> holder;
+  CHECK(arguments->GetHolder(&holder));
+  v8::Local<v8::Context> context = holder->CreationContext();
+
+  std::vector<v8::Local<v8::Value>> argument_list;
+  if (arguments->Length() > 0) {
+    // Just copying handles should never fail.
+    CHECK(arguments->GetRemaining(&argument_list));
+  }
+
+  std::unique_ptr<base::ListValue> converted_arguments;
+  v8::Local<v8::Function> callback;
+  std::string error;
+
+  if (!api_custom_types::GetFunctionSchema("types", "types.ChromeSetting",
+                                           method_name)
+           .ParseArgumentsToJSON(context, argument_list, *type_refs_,
+                                 &converted_arguments, &callback, &error)) {
+    arguments->ThrowTypeError("Invalid invocation");
+    return;
+  }
+
+  converted_arguments->Insert(0u, base::MakeUnique<base::Value>(pref_name_));
+  request_handler_->StartRequest(context, "types.ChromeSetting." + method_name,
+                                 std::move(converted_arguments), callback,
+                                 v8::Local<v8::Function>());
+}
+
+}  // namespace extensions