Make extensions developer mode warning controllable by experiments

chrome/browser/extensions/install_verifier.h

Index: chrome/browser/extensions/install_verifier.h
diff --git a/chrome/browser/extensions/install_verifier.h b/chrome/browser/extensions/install_verifier.h
index 778a1a6069b38a3db2a5d101358c84edb6fad0cf..b5a922502ad647d6e6ffe9522e4433c3fac3e329 100644
--- a/chrome/browser/extensions/install_verifier.h
+++ b/chrome/browser/extensions/install_verifier.h
@@ -45,6 +45,9 @@ class InstallVerifier : public ManagementPolicy::Provider {
   InstallVerifier(ExtensionPrefs* prefs, content::BrowserContext* context);
   ~InstallVerifier() override;
 
+  // Returns whether install verification should be enforced.
+  static bool ShouldEnforce();
+
   // Returns whether |extension| is of a type that needs verification.
   static bool NeedsVerification(const Extension& extension);