Extensions: Pass current channel and feature session type to extension unpack utility process.

extensions/common/extension_unpacker.mojom

 // 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.
 
 // Safe chrome extension unpacker service provided by the utility process
 // and exposed by mojo policy to the chrome browser process.
 
 module extensions.mojom;
 
 import "mojo/common/file_path.mojom";
 import "mojo/common/string16.mojom";
 import "mojo/common/values.mojom";
 
 interface ExtensionUnpacker {
   // Unzip |file| into the directory |path|.
   Unzip(mojo.common.mojom.FilePath file,
         mojo.common.mojom.FilePath path) => (bool success);
 
   // Unpack and sanitize the extension in directory |path|, and return its
   // parsed manifest.json file in |manifest|. The supplied |location|, and
   // and the |creation_flags| defined by Extension::InitFromValueFlags are
   // passed into Extension::Create() when unpacking the extension. Decoded
   // image and message catalog data from the extension is written to files
   // kDecodedImagesFilename and kDecodedMessageCatalogsFilename in |path|.
   // If Unpack() fails for any reason, |error| contains a user-displayable
   // explanation of what went wrong.
-  Unpack(mojo.common.mojom.FilePath path,
+  // |channel| and |type| are needed to initialize the global state of the
+  // extension system, which is needed while creating the Extension object.
+  Unpack(FeatureChannel channel,
+         FeatureSessionType type,
+         mojo.common.mojom.FilePath path,
          string extension_id,
          ManifestLocation location,
          int32 creation_flags)
       => (mojo.common.mojom.String16 error,
           mojo.common.mojom.DictionaryValue? manifest);
 };
 
 [Native]
 enum ManifestLocation;
+
+[Native]
+enum FeatureChannel;
+
+[Native]
+enum FeatureSessionType;