Add pref for crostini USB Device sharing settings

Bug: 899568
Change-Id: Ida5e475179d77010956a59411cc4872973fc18f4
Reviewed-on: https://chromium-review.googlesource.com/c/1345699
Commit-Queue: Josh Pratt <jopra@chromium.org>
Reviewed-by: Nicholas Verne <nverne@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613431}

chrome/browser/chromeos/crostini/crostini_pref_names.cc

@@ -16,6 +16,10 @@ const char kCrostiniMimeTypes[] = "crostini.mime_types";
 const char kCrostiniRegistry[] = "crostini.registry";
 // List of filesystem paths that are shared with the crostini container.
 const char kCrostiniSharedPaths[] = "crostini.shared_paths";
+// List of USB devices with their system guid, a name/description and their
+// enabled state for use with Crostini.
+const char kCrostiniSharedUsbDevices[] = "crostini.shared_usb_devices";
+
 // A boolean preference representing a user level enterprise policy to enable
 // Crostini use.
 const char kUserCrostiniAllowedByPolicy[] = "crostini.user_allowed_by_policy";
@@ -36,6 +40,7 @@ void RegisterProfilePrefs(PrefRegistrySimple* registry) {
   registry->RegisterDictionaryPref(kCrostiniMimeTypes);
   registry->RegisterDictionaryPref(kCrostiniRegistry);
   registry->RegisterListPref(kCrostiniSharedPaths);
+  registry->RegisterListPref(kCrostiniSharedUsbDevices);
   registry->RegisterBooleanPref(crostini::prefs::kReportCrostiniUsageEnabled,
                                 false);
   registry->RegisterStringPref(kCrostiniLastLaunchVersion, std::string());

chrome/browser/chromeos/crostini/crostini_pref_names.h

@@ -14,6 +14,8 @@ extern const char kCrostiniEnabled[];
 extern const char kCrostiniMimeTypes[];
 extern const char kCrostiniRegistry[];
 extern const char kCrostiniSharedPaths[];
+extern const char kCrostiniSharedUsbDevices[];
+
 extern const char kUserCrostiniAllowedByPolicy[];
 
 extern const char kReportCrostiniUsageEnabled[];

chrome/browser/extensions/api/settings_private/prefs_util.cc

@@ -368,6 +368,8 @@ const PrefsUtil::TypedPrefMap& PrefsUtil::GetWhitelistedKeys() {
       settings_api::PrefType::PREF_TYPE_BOOLEAN;
   (*s_whitelist)[crostini::prefs::kCrostiniSharedPaths] =
       settings_api::PrefType::PREF_TYPE_LIST;
+  (*s_whitelist)[crostini::prefs::kCrostiniSharedUsbDevices] =
+      settings_api::PrefType::PREF_TYPE_LIST;
 
   // Android Apps.
   (*s_whitelist)[arc::prefs::kArcEnabled] =