Windows install_static refactor.

chrome/install_static/install_constants.h

+// Copyright 2016 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.
+
+// Defines the struct used to describe each of a brand's install modes.
+
+#ifndef CHROME_INSTALL_STATIC_INSTALL_CONSTANTS_H_
+#define CHROME_INSTALL_STATIC_INSTALL_CONSTANTS_H_
+
+namespace install_static {
+
+// Identifies different strategies for determining an update channel.
+enum class ChannelStrategy {
+  // Update channels are not supported. This value is for exclusive use by
+  // brands that do not integrate with Google Update.
+  UNSUPPORTED,
+  // Update channel is determined by parsing the "ap" value in the registry.
+  ADDITIONAL_PARAMETERS,
+  // Update channel is a fixed value.
+  FIXED,
+};
+
+// A POD-struct defining constants for a brand's install mode. A brand may have

[robertshield, 2016/10/17 05:27:23]

Please elaborate somewhat extensively here on what is meant by "install mode".
This struct seems to contain most of the state one has to keep in their head
today to understand what kind of Chrome install is present. Documenting the snot
out of this (with examples), will serve posterity for years to come.

It might be helpful to describe a few common examples of installs today (Stable,
Dev/Beta, Canary, User / System) and describe what their InstallConstants would
look like. 

[grt (UTC plus 2), 2016/10/24 11:17:51]

Comment added to top of file. My hope is that the reader will also look toward
README.md.
Point taken, and docs added.
I will direct the reader to the definitions rather than restate them here.

+// one primary and many secondary install modes.
+struct InstallConstants {
+  // The brand-specific index/identifier of this instance (defined in a brand's
+  // BRAND_install_modes.h file). Index 0 is reserved for a brand's primary
+  // install mode.
+  int index;
+
+  // The install suffix of a secondary mode (e.g., " SxS" for canary Chrome) or
+  // an empty string for the primary mode.
+  const wchar_t* install_suffix;
+
+  // The app guid with which this mode is registered with Google Update, or an
+  // empty string if the brand does not integrate with Google Update.
+  const wchar_t* app_guid;
+
+  // The default name for this mode's update channel.
+  const wchar_t* default_channel_name;
+
+  // The strategy used to determine the mode's update channel, or UNSUPPORTED if
+  // the brand does not integrate with Google Update.
+  ChannelStrategy channel_strategy;
+
+  // True if this mode supports system-level installs.
+  bool supports_system_level;
+
+  // True if this mode supports multi-install.
+  bool supports_multi_install;
+};

[robertshield, 2016/10/17 05:27:23]

does is_msi() belong here for msi managed installs?

[grt (UTC plus 2), 2016/10/24 11:17:51]

No, since that varies based on install-time factors rather than brand-specific
build-time factors. That would be a candidate for InstallDetails, although I am
thinking I'll keep that in a setup-specific location since I hope that the
product itself will never need to know whether it originates from the .msi or
not.

+
+}  // namespace install_static
+
+#endif  // CHROME_INSTALL_STATIC_INSTALL_CONSTANTS_H_