Adding check to ensure onboarding content is not shown to supervised users.

chrome/browser/ui/startup/startup_tab_provider.h

Index: chrome/browser/ui/startup/startup_tab_provider.h
diff --git a/chrome/browser/ui/startup/startup_tab_provider.h b/chrome/browser/ui/startup/startup_tab_provider.h
index 96004fea07588a2cbf756b21bc63661b228e906b..4ecc3aa3ae731914a948ddbc546979289ddf8451 100644
--- a/chrome/browser/ui/startup/startup_tab_provider.h
+++ b/chrome/browser/ui/startup/startup_tab_provider.h
@@ -63,7 +63,8 @@ class StartupTabProviderImpl : public StartupTabProvider {
   static StartupTabs CheckStandardOnboardingTabPolicy(
       bool is_first_run,
       bool has_seen_welcome_page,
-      bool is_signed_in);
+      bool is_signed_in,
+      bool is_supervised_user);

[Peter Kasting, 2017/01/12 18:28:19]

Random muse: It seems like there are now a number of places in the startup code
that pass a bunch of bools around.  I wonder if any of these would read more
clearly (and safely) at callers/test sites if they used enums, or passed a
struct with named members, or something.

 
 #if defined(OS_WIN)
   // Determines which tabs should be shown according to onboarding/first run
@@ -74,7 +75,8 @@ class StartupTabProviderImpl : public StartupTabProvider {
       bool has_seen_win10_promo,
       bool is_signed_in,
       bool set_default_browser_allowed,
-      bool is_default_browser);
+      bool is_default_browser,
+      bool is_supervised_user);
 #endif
 
   // Processes first run URLs specified in Master Preferences file, replacing