Chrome app manifest support for action handlers.

extensions/common/manifest_handlers/action_handlers_handler.cc

+// Copyright (c) 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/common/manifest_handlers/action_handlers_handler.h"
+
+#include <memory>
+
+#include "base/memory/ptr_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "extensions/common/error_utils.h"
+#include "extensions/common/manifest_constants.h"
+
+namespace extensions {
+
+namespace app_runtime = api::app_runtime;
+namespace errors = manifest_errors;
+namespace keys = manifest_keys;
+
+// static
+std::set<app_runtime::ActionType> ActionHandlersInfo::GetActionHandlers(

[Daniel Erat, 2017/01/12 23:55:03]

i take it that this can't return a const reference since the extension may not
have any handlers, right? could you avoid the copy by changing this to:

  bool ActionHandlersInfo::HasActionHandler(const Extension* extension,
                                            app_runtime::ActionType);

? that's all that you use it for right now, right? do you envision needing to be
able to fetch the full list of handlers in the future?

[jdufault, 2017/01/14 00:30:42]

Done. Tests need the full set of handlers, so I moved this code into the test
file.

+    const Extension* extension) {
+  ActionHandlersInfo* info = static_cast<ActionHandlersInfo*>(
+      extension->GetManifestData(keys::kActionHandlers));
+  return info ? info->action_handlers : std::set<app_runtime::ActionType>();
+}
+
+ActionHandlersInfo::ActionHandlersInfo() = default;
+
+ActionHandlersInfo::~ActionHandlersInfo() = default;
+
+ActionHandlersHandler::ActionHandlersHandler() = default;
+
+ActionHandlersHandler::~ActionHandlersHandler() = default;
+
+bool ActionHandlersHandler::Parse(Extension* extension, base::string16* error) {
+  auto info = base::MakeUnique<ActionHandlersInfo>();
+  const base::ListValue* entries = nullptr;
+  if (!extension->manifest()->GetList(keys::kActionHandlers, &entries)) {
+    *error = base::ASCIIToUTF16(errors::kInvalidActionHandlersType);
+    return false;
+  }
+
+  for (const std::unique_ptr<base::Value>& wrapped_value : *entries) {
+    std::string value;
+    if (!wrapped_value->GetAsString(&value)) {
+      *error = base::ASCIIToUTF16(errors::kInvalidActionHandlersType);
+      return false;
+    }
+
+    app_runtime::ActionType action_type = app_runtime::ParseActionType(value);
+    if (action_type == app_runtime::ACTION_TYPE_NONE) {
+      *error = ErrorUtils::FormatErrorMessageUTF16(
+          errors::kInvalidActionHandlersActionType, value);
+      return false;
+    }
+
+    info->action_handlers.insert(action_type);
+  }
+
+  extension->SetManifestData(keys::kActionHandlers, info.release());
+  return true;
+}
+
+const std::vector<std::string> ActionHandlersHandler::Keys() const {
+  return SingleKey(keys::kActionHandlers);
+}
+
+}  // namespace extensions