First checkin of Crostini app model builder and related classes.

This is placeholder only and the button doesn't yet connect to any action.

Bug: 813699
Change-Id: Idc84916be75ee25ac1f570a5917af8363f6f5655
Reviewed-on: https://chromium-review.googlesource.com/925921
Commit-Queue: Nicholas Verne <[email protected]>
Reviewed-by: James Cook <[email protected]>
Reviewed-by: calamity <[email protected]>
Reviewed-by: Ben Wells <[email protected]>
Cr-Commit-Position: refs/heads/master@{#538296}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 3cc3bee..76d8e9f 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -3737,6 +3737,10 @@
      flag_descriptions::kAshEnableNewOverviewAnimationsName,
      flag_descriptions::kAshEnableNewOverviewAnimationsDescription, kOsCrOS,
      SINGLE_VALUE_TYPE(ash::switches::kAshEnableNewOverviewAnimations)},
+    {"enable-experimental-crostini-ui",
+     flag_descriptions::kExperimentalCrostiniUIName,
+     flag_descriptions::kExperimentalCrostiniUIDescription, kOsCrOS,
+     FEATURE_VALUE_TYPE(features::kExperimentalCrostiniUI)},
 #endif  // OS_CHROMEOS
 
 #if defined(OS_ANDROID)